Wildguzzi.com
General Category => General Discussion => Topic started by: spiggs on January 01, 2024, 01:04:07 PM
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Hi All. Just picked up this neglected Le Mans CX100 and the prior owner was an engineer who loved to mod his bikes. He passed away around 15 years ago so I can't ask the original owner anymore so I am looking for information about the modifications done. Most interesting are the wheels and brakes. I have never seen a setup like this. The wheels are wider than the originals, forks stanchions measure the same as stock but the lowers are custom or had the brake caliper bosses shaved off and replaced by a mounting setup that consists of a plate that floats free of the lower fork leg and is anchored by the strut mounted to a bracket below the triple clamp. The rear swing arm is chrome plated so may also be non-stock? Other pictures show the solex carb mod, not sure if this was ever hooked up, and the oil cooler. So where these common modifications or something fabricated by the prior owner? Spot anything else odd? I am sure as I go through this bike other things will pop up. I think I have almost all the parts for the bike. From the condition of the fuel tank it looks like the prior owner was in the middle of shaving the emblems off the bike when the project stopped along with the carb install.
Also this is my first Guzzi. Luckily included with the bike is a pile of shop manuals so I have some guidance to follow. Where are the good parts sources for these older Guzzi's?
Thanks for the help.
(https://i.ibb.co/FhR9knP/lemans-front-brake.jpg) (https://ibb.co/FhR9knP)
(https://i.ibb.co/mcXc7d8/lemans-oil-cooler.jpg) (https://ibb.co/mcXc7d8)
(https://i.ibb.co/gv9921G/lemans-rear-brake.jpg) (https://ibb.co/gv9921G)
(https://i.ibb.co/F4hBK86/lemans-solex-carb.jpg) (https://ibb.co/F4hBK86)
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Wow, I've never seen those kind of modifications. If you have the original parts I'd just put it back together as per the factory and if it were me I'd strip it down to the frame and have it painted or powder coated, new wiring harness from Greg Bender and of course new paint on the tank, etc. I would also rebuild the engine and open the transmission, etc.
Keep in mind that this model does not usually get much money at resale compared to a LM I so watch what you spend. Unless you plan on keeping the bike, then I'd take the high road.
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I have the stock wheels but not the lower fork legs. I don't know if those are the original Brembo calipers or not. Bike came with a spare Brembo caliper of some sort as well. I don't see any markings on the wheels to know what they are.
If the solex carb was a known good mod I would keep it but if not would stick the stock carbs back on. I have a feeling it still needs to be jetted and sorted if I were to go down that route. Bike still has stock exhaust so I don't imagine anything to wild was done to the engine.
The plan is to strip it down to the frame and go through everything. This will be a fun project for me. Not planning to ever make my money back, just create a nice Guzzi to ride and show.
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I'll take the wheels!
Seriously though, those look like EPM magnesuim wheels. Did the previous owner race this thing? Don't know why it would need an oil cooler. I've never seen floating calipers on a front fork like that. The carb is interesting too.
Really cools guzzi you have there. Someone might know this bike.
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What Black cat said. It's not a terribly "desirable" Guzzi, although a nice one. I never have seen a Solex on a Guzzi FWIW. Normally, if you haven't seen one, there is a reason for that. :smiley: I understand that magnesium wheels are too fragile for a street bike.. but maybe an old wife told me that.
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"I don't know if those are the original Brembo calipers or not"
Can't really see what those are but the original Brembo calipers on the CX had dual bleeders.
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Maybe he went through all those fork and brake mods to get those EPM wheels to fit? How wide are they?
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Whats with the push-pull rod going from the frame to the rear caliper mounting bracket??!! So, the bracket moves/pivots on the axle in
unison with the rear frame?? I wonder how well that works as compared to the caliper bracket remaining stationary and moving in unision with the swing arm? Oh well, interesting complex project for 1st time Guzzista, good luck!
Art
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Front end mods look like a home-brewed mechanical anti-dive to me, rear looks like a floating caliper setup.
Long intake runners with that Solex setup, might be good for torque, probably hard to get jetting right though.
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Maybe he went through all those fork and brake mods to get those EPM wheels to fit? How wide are they?
Well with the tires mounted can't get the real measurement but the outside front is 3" and the rear 3.5" compared to 2.7" at the same point for the stock rims. So perhaps a 1/4 inch wider in the front and 3/4 inch wider in the rear.
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Front end mods look like a home-brewed mechanical anti-dive to me, rear looks like a floating caliper setup.
Long intake runners with that Solex setup, might be good for torque, probably hard to get jetting right though.
And unequal length with how the carb is mounted so each cylinder would have a slightly different power curve.
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I wonder if there were any engine mods?
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I wonder if there were any engine mods?
Don't know what the ports look like stock but the ones on this engine are really smooth so maybe some port work at least.
(https://i.ibb.co/fX2kk9v/lemans-intake.jpg) (https://ibb.co/fX2kk9v)
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looks to me like someone has been in there. Here are some intake pictures from heads I've had done.
small valve Mild porting-
(https://i.ibb.co/8PGSbHM/850T-4.jpg) (https://ibb.co/8PGSbHM)
big valve heavy porting
(https://i.ibb.co/k9vRgqk/heads-4.jpg) (https://ibb.co/k9vRgqk)
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looks to me like someone has been in there. Here are some intake pictures from heads I've had done.
small valve Mild porting-
(https://i.ibb.co/8PGSbHM/850T-4.jpg) (https://ibb.co/8PGSbHM)
big valve heavy porting
(https://i.ibb.co/k9vRgqk/heads-4.jpg) (https://ibb.co/k9vRgqk)
I guess with everything else done to the bike it would be odd if the engine was untouched. The intake port measures 33mm at the inlet, Solex carb is a 36mm. Exhaust looks stock unless it is parts from a different Guzzi. Bike came with a number of Solex/Mikuni tuning manuals and a manual for an exhaust gas analyzer but again have no idea what the last running setup was. Bike also has a spare brand new Solex carb so I could compare the jets in each to see if any tuning was done. Sounds like the prior owner was going his own way with this setup. I think my preference though would be to put the stock carbs back on if they would work acceptably with the current setup but of course what I really need to do is tear into the engine and evaluate the rest.
"I don't know if those are the original Brembo calipers or not"
Can't really see what those are but the original Brembo calipers on the CX had dual bleeders.
They are not stock then. The caliper in the box has dual bleeders. The ones on the bike have a single bleeder next to the brake line inlet.
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What is with the sump? Alt cover? Oil pressure sender? Lots of interesting things to see.
TdF
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Will follow the resurrection with interest. If the wheels are indeed magnesium, I personally would be very reluctant to use them since they can become very brittle with time.
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The front brake linkage was a popular anti-dive mod in the late 80s, IIRC.
The rear linkage would be pro-squat, but I've never seen that used before and don't know how effective it would be.
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The front brake linkage was a popular anti-dive mod in the late 80s, IIRC.
The rear linkage would be pro-squat, but I've never seen that used before and don't know how effective it would be.
Front end mods look like a home-brewed mechanical anti-dive to me, rear looks like a floating caliper setup.
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Thanks, that makes a lot of sense. So do you think this was a kit that was available or did the prior owner fab it?
Will follow the resurrection with interest. If the wheels are indeed magnesium, I personally would be very reluctant to use them since they can become very brittle with time.
Yeah I do worry about that. Looking up EPM wheels brings me to a page that says they were available in magnesium or aluminum. Any easy way to tell which these are?
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Looking up EPM wheels brings me to a page that says they were available in magnesium or aluminum. Any easy way to tell which these are?
Find a bare bit of the wheel and place a drop of vinager on it. If it bubbles it's magnesium, if not it's aluminium. Rinse well afterwards.
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Someone was racing that… mag wheels, oil cooler, anti-dive Earles front fork
(https://i.ibb.co/jDQp5mq/IMG-0976.jpg) (https://ibb.co/jDQp5mq)
(https://i.ibb.co/j5x7Z3T/IMG-0920.jpg) (https://ibb.co/j5x7Z3T)
Some fotos came thru Facebook lately of Freddie Spencer on a guzzi testing
I’ll go look
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On a 1st series le man…
(https://i.ibb.co/nMTXPxM/IMG-0977.jpg) (https://ibb.co/nMTXPxM)
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Intake ports would be stock for a small valve head.
(https://i.ibb.co/Hnc3hz1/850-Le-Mans-heads-4.jpg) (https://ibb.co/Hnc3hz1)
Your pic makes me suspect he raised the top of the port.
Mikuni carbs can be a really nice upgrade on a sporting Guzzi. A single dual throat carb is a new one to me, but then again Guzzi went to a single dual throat throttle body on the Quota 1100 and some more recent offerings.
The former owner might have been a genius or a nut job. It might be worth inspecting, refreshing, and running what's there to see how well it works. (especially if you have a brand new carb).
Check those wheels.
I think it would be really cool bike as it sits, especially if it was raced like Chuck is suggesting.
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Can you send a pic of the entire bike? :popcorn:
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looks like a hollow front axle as well, very interesting, there must also be internal sump mods to accommodate that oil cooler. As for the calipers I think there may have been a mix according to what they had, my rear was twin bleeder my fronts were single bleeder.
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If it is a race bike I wonder why the discs aren't drilled?
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Look at the sump! The fins look really thick and the drain plug is on the left side. What company made that?
There is a lot going on here.
Too cool!
Also, the carb - https://www.mikunipower.com/PHH01.htm (https://www.mikunipower.com/PHH01.htm) Thought it looked like a weber sidedraft.
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Do you know who owned the bike? Good chance someone here knew him. I know Mike Tiberio put Mikunis on at least one of his bikes. (As an aside, not implying this was one of Mike's bikes).
-AJ
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Someone was racing that… mag wheels, oil cooler, anti-dive Earles front fork
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Besides those parts I don't have any info that points to it being raced and in fact a few things that say it wasn't besides maybe track days. Talking to the daughter of the prior owner she never mentioned racing, it has all the original body work (heavy), no evidence of safety wires on bolt heads etc.
Do you know who owned the bike? Good chance someone here knew him. I know Mike Tiberio put Mikunis on at least one of his bikes. (As an aside, not implying this was one of Mike's bikes).
-AJ
The name George Lieblang is on some of the paperwork I have with the bike.
Look at the sump! The fins look really thick and the drain plug is on the left side. What company made that?
There is a lot going on here.
Too cool!
Also, the carb - https://www.mikunipower.com/PHH01.htm (https://www.mikunipower.com/PHH01.htm) Thought it looked like a weber sidedraft.
Yep, carb is like a mini Weber DCOE. Mikuni PHH 36 as you found. A friend of mine had a set of PHH 44 on a Fiat 1300 SOHC engine years ago. Those were the same size as the DCOE.
Intake ports would be stock for a small valve head.
(https://i.ibb.co/Hnc3hz1/850-Le-Mans-heads-4.jpg) (https://ibb.co/Hnc3hz1)
Your pic makes me suspect he raised the top of the port.
Mikuni carbs can be a really nice upgrade on a sporting Guzzi. A single dual throat carb is a new one to me, but then again Guzzi went to a single dual throat throttle body on the Quota 1100 and some more recent offerings.
The former owner might have been a genius or a nut job. It might be worth inspecting, refreshing, and running what's there to see how well it works. (especially if you have a brand new carb).
Check those wheels.
I think it would be really cool bike as it sits, especially if it was raced like Chuck is suggesting.
Thanks for the measurements. So a light porting if any. Former owner worked in aerospace for a number of years then formed his own engineering company. From what I understand had a long history of modifying motorcycles. Carb setup reminds me of the Ducati Paso with the single Weber DCNF 44. Again not sure if it was ever running with the Mikuni PHH. There is no throttle linkage hooked up and I have not found the rest of the intake manifolds to connect everything together.
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Can you send a pic of the entire bike? :popcorn:
Here you go. A bunch of pics of how I got the bike. Sorry have not had time to give it a first clean up yet. Hopefully this weekend I can give it a wash and see if I can find any new details. Really appreciate all the input.
(https://i.ibb.co/xMJRT1c/lemans-air-fork.jpg) (https://ibb.co/xMJRT1c) (https://i.ibb.co/FHcvvr6/lemans-batt.jpg) (https://ibb.co/FHcvvr6) (https://i.ibb.co/D5RmZDJ/lemans-box.jpg) (https://ibb.co/D5RmZDJ) (https://i.ibb.co/9s08NS2/lemans-dash.jpg) (https://ibb.co/9s08NS2) (https://i.ibb.co/DrShbMm/lemans-front-left.jpg) (https://ibb.co/DrShbMm) (https://i.ibb.co/fpb0sHd/lemans-front-right.jpg) (https://ibb.co/fpb0sHd) (https://i.ibb.co/4RLycwW/lemans-full-rear.jpg) (https://ibb.co/4RLycwW) (https://i.ibb.co/pydwnQf/lemans-left-rear.jpg) (https://ibb.co/pydwnQf) (https://i.ibb.co/WcX29Z5/lemans-mid-left.jpg) (https://ibb.co/WcX29Z5) (https://i.ibb.co/SvRCf3F/lemans-right-mid.jpg) (https://ibb.co/SvRCf3F) (https://i.ibb.co/JswQHLh/lemans-right-rear.jpg) (https://ibb.co/JswQHLh) (https://i.ibb.co/vYBZ02V/lemans-shifter.jpg) (https://ibb.co/vYBZ02V) (https://i.ibb.co/P65bwxF/lemans-shift-link.jpg) (https://ibb.co/P65bwxF) (https://i.ibb.co/W3cMPnF/lemans-steer-head.jpg) (https://ibb.co/W3cMPnF) (https://i.ibb.co/XxXZCB5/lemans-sump-back.jpg) (https://ibb.co/XxXZCB5) (https://i.ibb.co/HpZRfNZ/lemans-sump-front.jpg) (https://ibb.co/HpZRfNZ) (https://i.ibb.co/z7gj6xX/mikuni-phh-36.jpg) (https://ibb.co/z7gj6xX)
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Lots of interesting modifications done there....quite intriguing !
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Aerospace engineering eh?
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bike looks good next to that x9.. i think you should sell that air head, and slide a non running Alfa in its place. then you entire garage will be beautifully annoying ! :boozing:
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Whats with the push-pull rod going from the frame to the rear caliper mounting bracket??!! So, the bracket moves/pivots on the axle in
unison with the rear frame?? I wonder how well that works as compared to the caliper bracket remaining stationary and moving in unision with the swing arm? Oh well, interesting complex project for 1st time Guzzista, good luck!
Art
The floating rear brake caliper is a common modification. The force gets routed through the frame rather than through the swingarm and improves rear suspension performance. Common on race bikes.
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Hi All. Just picked up this neglected Le Mans CX100 and the prior owner was an engineer who loved to mod his bikes. He passed away around 15 years ago so I can't ask the original owner anymore so I am looking for information about the modifications done. Most interesting are the wheels and brakes. I have never seen a setup like this. The wheels are wider than the originals, forks stanchions measure the same as stock but the lowers are custom or had the brake caliper bosses shaved off and replaced by a mounting setup that consists of a plate that floats free of the lower fork leg and is anchored by the strut mounted to a bracket below the triple clamp. The rear swing arm is chrome plated so may also be non-stock? Other pictures show the solex carb mod, not sure if this was ever hooked up, and the oil cooler. So where these common modifications or something fabricated by the prior owner? Spot anything else odd? I am sure as I go through this bike other things will pop up. I think I have almost all the parts for the bike. From the condition of the fuel tank it looks like the prior owner was in the middle of shaving the emblems off the bike when the project stopped along with the carb install.
Also this is my first Guzzi. Luckily included with the bike is a pile of shop manuals so I have some guidance to follow. Where are the good parts sources for these older Guzzi's?
Thanks for the help.
(https://i.ibb.co/FhR9knP/lemans-front-brake.jpg) (https://ibb.co/FhR9knP)
(https://i.ibb.co/mcXc7d8/lemans-oil-cooler.jpg) (https://ibb.co/mcXc7d8)
(https://i.ibb.co/gv9921G/lemans-rear-brake.jpg) (https://ibb.co/gv9921G)
(https://i.ibb.co/F4hBK86/lemans-solex-carb.jpg) (https://ibb.co/F4hBK86)
The front floating brake setup is for anti-dive. This may have been a race bike, or at least a racer who was performing '80s/'90s racer mods to his streetbike
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That might be a modified BUB sump.
information here - https://wildguzzi.com/forum/index.php?topic=93470.0 (https://wildguzzi.com/forum/index.php?topic=93470.0)
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That might be a modified BUB sump.
information here - https://wildguzzi.com/forum/index.php?topic=93470.0 (https://wildguzzi.com/forum/index.php?topic=93470.0)
That sure looks like it. Those rubber hoses and barb fittings in that sump terrify me. Of course seeing as how the one on my bike was modified I won't know what is inside until I drop the sump.
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Just looked at the frame and engine numbers. Frame matches the pink but the engine does not. Engine serial is VG206927. What is that engine from? A web search seems to point to a SP1000? Any idea what year and what differences would it have compared to the original engine?
(https://i.ibb.co/27J5yHm/lemans-engine-number.jpg) (https://ibb.co/27J5yHm)
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The CX100 came with the same engine as the SP IIRC. It was down to emissions, I believe, that preventet Guzzi from using the Le Mans engine. And/or it had to do with homologation, that it was too costly to have the Le Mans engine approved compared to how many units they could expect to sell.
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Not sure if that version is quite right as the LM 2 engine is exactly the same as the LM 1 which was homologated. So it would have been importable as an 850 cc just like the Euro bikes. But the US market wanted a 1000cc machine and to satiate that they simply put the G5/SP lump into a LM2 frame and called it the CX.
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Just looked at the frame and engine numbers. Frame matches the pink but the engine does not. Engine serial is VG206927. What is that engine from? A web search seems to point to a SP1000? Any idea what year and what differences would it have compared to the original engine?
(https://i.ibb.co/27J5yHm/lemans-engine-number.jpg) (https://ibb.co/27J5yHm)
SP 1000 engine numbers were VG 18781 - VG 25693
According to Greg Bender's site, CX 100 began with "VU 111383 - ........"
On your frame and title, do you have "VU" after "ZGU" ??
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The floating rear brake caliper is a common modification. The force gets routed through the frame rather than through the swingarm and improves rear suspension performance. Common on race bikes.
Oh, interesting! I get the floating caliper part but was unaware of expressing that force up to the frame.
Zero track time here,
Art
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Oh, interesting! I get the floating caliper part but was unaware of expressing that force up to the frame.
Zero track time here,
Art
Most of the time, they used to run the rod forward to the lower frame rail, as on the Daytona and 900ss pictured below. On the subject bike, the link runs upward, apparently trying to counter rear end rise under braking.
(https://i.ibb.co/t3XBKFB/1993-Motor-Guzzi-Daytona-34.jpg) (https://ibb.co/t3XBKFB)
(https://i.ibb.co/pZJQCG3/Ducati-900-SS-Final-Edition-Right-Side-1.webp) (https://ibb.co/pZJQCG3)
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SP 1000 engine numbers were VG 18781 - VG 25693
According to Greg Bender's site, CX 100 began with "VU 111383 - ........"
On your frame and title, do you have "VU" after "ZGU" ??
The frame and title are assigned VU 111449, original engine was T51461 according to the title.
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Not sure if that version is quite right as the LM 2 engine is exactly the same as the LM 1 which was homologated. So it would have been importable as an 850 cc just like the Euro bikes. But the US market wanted a 1000cc machine and to satiate that they simply put the G5/SP lump into a LM2 frame and called it the CX.
I can only reiterate what I have read, specifically in Cycle magazine, since I do not have any first hand knowledge. Below are exempts from their July, 1980, edition:
...the 850 was replaced by a one-liter version, called the Le Mans CX100. A couple of reasons prompted the displacement increase... For starters, the EPA was writing ever-tighter rules for motorcycle exhaust emissions. (This) would make the 850 too slow..... Second, the...US importer found themselves faced with ushering...three engines through the EPA tests. The V50...the 850s and 1000s...the Le Mans was booted upstairs to enjoy life with new 475cc cylinders. This year's LM shares with the 1979 edition all but its 80 mph speedometer... 1980s LM shares the same powerplant as the 1000SP: both engines have 948.8cc...compressi on ratio is 9.2;1, significantly lower than the 10.2:1 ratio used in the 850 Le Mans...(CX100) drag-strip showing: 13.50 s @ 98.46 mph...the old 850 Le Mans: 13.08 s @ 103.21 mph...(The CX100) got between 35.1 and 51.1 mpg, 41.9 mpg average
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The frame and title are assigned VU 111449, original engine was T51461 according to the title.
T51461 sounds like the transmission number to me.
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T51461 sounds like the transmission number to me.
And so it is. Thanks. Looks like when the bike was titled they used the transmission number instead of the engine number. Which means the engine is most likely original. I need to have someone come out and verify the serial numbers to the pink slip and sign off before I can transfer the title since the bike is not in the system anymore. Guess I'll just point confidently to the transmission number when they ask where the engine's serial number is.
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Check those wheels.
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Checked the wheels and they are magnesium. Oh well I guess they will make good conversation pieces. I am hoping the brake hardware fits the stock wheels as well.
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I meant for you to check the wheels for cracks / damage. Not everyone will agree with me, but I wouldn't hang them on the wall just yet.
Back in the day there were cases of magnesium wheels failing on new bikes. The debate was Fatigue vs. Road conditions vs. abuse vs. build quality.
Not all magnesium wheels are created equally. I'd try contacting EPM first. See what they were using, and see what they recommend.
I'd perform my due diligence and if I decided to run them, keep a close eye on them for damage.
If you plan on riding through pothole city or Australia, then by all means swap back to the stock rims.
my 2 cents
http://www.magni.it/epm_6_razze.htm (http://www.magni.it/epm_6_razze.htm)
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Corrosion was the reason we scrapped many aircraft magnesium wheels. Mostly in the bead toe area if irc.
The scrap wheels are great party additions for a campfire if you have a small one. Stress corrosion cracking and intergranular exfoliation comes to mind
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You can strip the paint and have them x-rayed for hairline cracks, and inspected for corrosion. If good, you could reseal with the proper paint.
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I meant for you to check the wheels for cracks / damage. Not everyone will agree with me, but I wouldn't hang them on the wall just yet.
Back in the day there were cases of magnesium wheels failing on new bikes. The debate was Fatigue vs. Road conditions vs. abuse vs. build quality.
Not all magnesium wheels are created equally. I'd try contacting EPM first. See what they were using, and see what they recommend.
I'd perform my due diligence and if I decided to run them, keep a close eye on them for damage.
If you plan on riding through pothole city or Australia, then by all means swap back to the stock rims.
my 2 cents
http://www.magni.it/epm_6_razze.htm (http://www.magni.it/epm_6_razze.htm)
Thanks for the link and advice. I will reach out to the company and see what they say and go from there. Would be great if I can use them.
Anyone recognize the brake rotors? They are not magnetic and have a dull finish to them. They do not look like iron or steel.
Also found a set of rear sets and the missing intake manifold pieces in a box.
(https://i.ibb.co/dp4cwg1/lemans-rearsets.jpg) (https://ibb.co/dp4cwg1)
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In the airplane shop we dealt with magnesium engine cases from time to time. They were almost always structurally sound but usually looked a bit rough. We didn't xray but checked them carefully for cracks etc with Zyglo and black light. The boss always said magnesium is always trying to return to earth.
kk
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I'm not familiar with those rear sets. They look the business. I'm not sure what intake pieces those are? for the Solex?
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I'm not familiar with those rear sets. They look the business. I'm not sure what intake pieces those are? for the Solex?
Yes for the Solex carb. Custom aluminum pipes to connect between the rubber manifolds at the head and carbs. An interesting setup since they are unequal length.
I had a chance to wash the bike and take a closer look at everything this weekend. I am now pretty sure this bike was a track bike or intended for the track or a masochistic owner. Looking at the way the battery was wired into the system there is no way it would carry enough current to support an electric starter and the starter is removed. So it was setup for using a starting roller or bump start only.
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Single carb manifolds for Guzzi’s have differences between left and right runners that I don’t understand. If you look at a single manifold from Sonny Angel the difference between the runners is obvious. The diameter and length are not symmetrical but I don’t remember what is the reason exactly, I expect part of it is the direction of airflow in combination with the degrees of rotation between power pulses. I won a Sonny Angel single carb setup complete with Mikuni carb at Ken’s Italy, TX rally . I never used it and donated to the Oklahoma rally . It ended up at Atlas Cycle, OK and don’t know if it was ever installed . I was told they were great for torque
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I don't know if it has ever been done on a motorcycle but different length manifolds can affect torque. For many, many years I thought the intake manifolds on the Chrysler Slant Sixes were a design merely to save costs. Not so as I found out not so long ago. The unequal length runners were designed to provide maximum torque at low rpm, long ones, and maximum horsepower at higher rpm, short ones, with a balance in the middle. I doubt a motorcycle manufacturer would bother doing something like this. though.
kk
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I don't know if it has ever been done on a motorcycle but different length manifolds can affect torque. For many, many years I thought the intake manifolds on the Chrysler Slant Sixes were a design merely to save costs. Not so as I found out not so long ago. The unequal length runners were designed to provide maximum torque at low rpm, long ones, and maximum horsepower at higher rpm, short ones, with a balance in the middle. I doubt a motorcycle manufacturer would bother doing something like this. though.
kk
The Scientific Design and Tuning of Intake and Exhaust Systems goes through that in detail with most of the testing done on a single 500 cc cylinder. Get a copy if it’s still in print - you won’t regret it
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Single carb manifolds for Guzzi’s have differences between left and right runners that I don’t understand. If you look at a single manifold from Sonny Angel the difference between the runners is obvious. The diameter and length are not symmetrical but I don’t remember what is the reason exactly, I expect part of it is the direction of airflow in combination with the degrees of rotation between power pulses. I won a Sonny Angel single carb setup complete with Mikuni carb at Ken’s Italy, TX rally . I never used it and donated to the Oklahoma rally . It ended up at Atlas Cycle, OK and don’t know if it was ever installed . I was told they were great for torque
With the way the intake on this bike was designed each barrel of the Solex feeds one cylinder so it acts the same as having 2 one barrel carbs. The differing lengths just seem to be because of packaging. Perhaps there was some thought on how long to make it so each runner would benefit the power curve in a usable range but to me it looks like packaging took precedence over optimal intake length.
The Scientific Design and Tuning of Intake and Exhaust Systems goes through that in detail with most of the testing done on a single 500 cc cylinder. Get a copy if it’s still in print - you won’t regret it
That does look like a good read.
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I measured the lift of the cam at the top of the intake rocker adjuster. The setup was quick and dirty but I measured .255" so I think this is close enough to tell me it has the stock cam in it (stock is .259" I think?) I also looked at the flywheel as best I could through the starter motor opening and did not note any machining. So stock cam, stock flywheel, stock size intake ports is telling me the engine is stock internally.
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Looks like something I should read. I read We Were The Ramchargers twice. Very interesting and educational read. These guys were Chrysler engineers who were interested in and participated in drag racing. They did a lot of tuning with intake and exhaust tuning through math and physics rather than just throwing stuff at an engine. They were very successful and shared everything with anyone racing the brand to make Chrysler successful on the drag strip. The win on Sunday sell on Monday thing. They did this on their own time with minimal support from the factory. They got a body in white once in awhile and maybe a long block from time to time. One of their early experiments, the High and Mighty. It set the record the 2nd time out I think. Rules were written to ban it on pressure from Ford and GM.
kk
(https://i.ibb.co/jTPnpL8/burnout.jpg) (https://ibb.co/jTPnpL8)
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The plot thickens!
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Looks like something I should read. I read We Were The Ramchargers twice. Very interesting and educational read. These guys were Chrysler engineers who were interested in and participated in drag racing. They did a lot of tuning with intake and exhaust tuning through math and physics rather than just throwing stuff at an engine. They were very successful and shared everything with anyone racing the brand to make Chrysler successful on the drag strip. The win on Sunday sell on Monday thing. They did this on their own time with minimal support from the factory. They got a body in white once in awhile and maybe a long block from time to time. One of their early experiments, the High and Mighty. It set the record the 2nd time out I think. Rules were written to ban it on pressure from Ford and GM.
kk
(https://i.ibb.co/jTPnpL8/burnout.jpg) (https://ibb.co/jTPnpL8)
I have read about their exploits before, the science works. Now if I wanted to go full Ramcharger with the Solex setup on this Guzzi I could redesign the intake length based on calculated values for peak torque then run it up and over the fuel tank.. The High and Mighty Guzzi intake!
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The plot thickens!
Yes it does. So this may seem silly but up until now I have not looked at the odometer. I haven't even thought about it and the gauges had a thick layer of dust that obscured the numbers. I gave the bike a quick wash over the weekend but didn't want to spray the gauges down with water so left them. Finally I took a cloth and some detail spray and gave them a quick wipe down. The odometer reads 25 miles, I felt a bit dumbfounded.
(https://i.ibb.co/8YZXkCV/lemans-odometer.jpg) (https://ibb.co/8YZXkCV)
So I can think of a number of scenarios.
The bike has 100,025 miles
The previous owner disconnected the odometer and rode/raced the bike that way from new
The gauge cluster is new or the odometer was reset
The bike was purchased to be a track bike but the prep was never completed and so it sat with 25 miles on it
Another piece of the puzzle. The tires on the original wheels have full tread, a date code of 150 which could mean the 15th week of 1980, and are the type that would have come on the bike originally. I think it is safe to say these were taken off early in this Guzzi's life. The tires on the EPM wheels are Michelin M45's with a date code of 519 with full tread. So they could have been manufactured on the 51st week of 1979, 1989. 1999 and are not the kind of tire you would put on the track.
Obviously I think it's highly unlikely this 43 year old bike has 25 miles on it. I wish the original pink slip had the engine number on it so I knew for sure if this is the original engine. I will also note that among the boxes is a stack of old head and cylinder base gaskets. All I can say is this was a project in progress, where in the process I don't know.
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Most likely is the speedo was replaced and the mileage is what was on the guage
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85mph speedometer. those we for model years 1981 and 1982 I believe. maybe 1980. Doubful for a bike built in 1979. If it was a replacement, it was probably cheap. The owner really was a guzzi guy!
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79 CX100s didn’t have the 85 mph speedo. I have one.
Compare the fluorescent orange needle tips on the speedo and tach, it may give you an idea of how new the speedo is in relation to the rest of the bike. The tips fade pretty fast in sunlight.
I’m not sure motorcycle tires had date codes in 1980.
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85mph speedometer. those we for model years 1981 and 1982 I believe. maybe 1980. Doubful for a bike built in 1979. If it was a replacement, it was probably cheap. The owner really was a guzzi guy!
The title says the bike is a 1980, the data plate on the bike lists mfg date? as 07/1980 and model year 1981 so I would think technically an early 81?
79 CX100s didn’t have the 85 mph speedo. I have one.
Compare the fluorescent orange needle tips on the speedo and tach, it may give you an idea of how new the speedo is in relation to the rest of the bike. The tips fade pretty fast in sunlight.
I’m not sure motorcycle tires had date codes in 1980.
Needle tips look relatively the same
(https://i.ibb.co/B3Kyxkz/lemans-gauges.jpg) (https://ibb.co/B3Kyxkz)
I did a search on how to read date codes and came up with the information that prior to year 2000 they were 3 digits and the last digit represented decade. It seems to follow the format that would say this is a date code but of course this is just based on internet search information. If it is a date code it could be 1980 or 1990 based on the last digit being decade. I was guessing 1980 because I found a contemporary review of the bike that listed the original spec tires as Pirelli Super Sport Gordon. Don't know if this was still a current model tire in 1990.
(https://i.ibb.co/g4rjd0Y/lemans-tire-1.jpg) (https://ibb.co/g4rjd0Y)
(https://i.ibb.co/MhZR42w/lemans-tire-2.jpg) (https://ibb.co/MhZR42w)
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Those are some old tires! Don't throw them out, someone may want them for a display bike / museum piece. I bet they are as hard as rocks!
I checked and it looks like the M18 Gordons came out in 1975. (thank you facebook). Your guess of 1980 is probably correct.
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The title says the bike is a 1980, the data plate on the bike lists mfg date? as 07/1980 and model year 1981 so I would think technically an early 81?
CX100s were built in two batches, 1979 and (I believe) 1980 models. I think there was maybe a year or a bit more between them. Yours looks to be from the second batch. There were some very minor differences between the two batches: other than the speedo one that comes to mind (from memory) is the method of manufacture of the fairings: the early ones were chopper gun fiberglass, rough on the inside. The later ones were smooth on the inside, and had slightly different lower brackets.
I would guess that your bike was run without the speedo for a while and then it was remounted on the bike. I bet it doesn’t have a lot of miles on it regardless, because anything you do with a bike minus speedo isn’t going to involve riding a lot of miles. The same might be true for the entire instrument cluster.
The Pirelli Gordon tires are original, the original wheels have probably never had another set of tires on them.
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I very much get the impression that this bike was a project early in it's life that never made it back on the road. How early I don't know. Like you said it may have been run without the gauges for a time, the previous owner did add an oil pressure gauge where I think the original clock would be. Maybe he even swapped the gauges at that time I will never know. There are just so many things partially complete. The brakes are decoupled but the back brake is not hooked up and the front master cylinder is still the stock 12mm unit. The Moto Guzzi badges are removed from the fuel tank and the mounting holes welded up and ground back but not painted, a Bosch blue ignition coil is mounted to the fairing but there is no wires to it, the carb conversion did not have a throttle cable hooked up nor a fuel line fabricated with it. Among the paperwork is a hand drawn wiring schematic and on the bike there are some wires that do not go anywhere. Just a bunch of stuff.
Well my goal will be to get this LeMans back on the road as a solid runner. Hopefully keeping some of it's uniqueness with the EPM wheels and anti dive front It's going to be a puzzle though.
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Do you have the original carbs? what do the intake manifolds look like? what throttle do you have, tomasselli 2C?
If the current solex carb was never run, then I suggest going back to something more conventional.
You could probably get decent $ for those Solex carbs. That would offset some of the costs.
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Do you have the original carbs? what do the intake manifolds look like? what throttle do you have, tomasselli 2C?
If the current solex carb was never run, then I suggest going back to something more conventional.
You could probably get decent $ for those Solex carbs. That would offset some of the costs.
I was thinking the same thing. I do have the original carbs and yes the throttle looks like the Tomasselli 2C. Attached is a pic of the intakes currently bolted to the heads. Don't know how much the Solex carbs are worth, hard to find any info about applications. There is probably someone who would pay reasonable money because of a specific application, just need to find that person.
(https://i.ibb.co/Y2vyYvF/lemans-intake.jpg) (https://ibb.co/Y2vyYvF)
On another note I think the brake discs I have are aluminum coated with iron from Harry Hunt. They got good reviews but I found some people mentioning that the iron coating can separate if moisture gets under it so I'll have to give them a good once over.
On the mechanical anti dive I have found references to the Preston Petty no-dive setup for off road bikes although some of the articles about his system mention his setup was used on some road race bikes as well. I also found info about Udo Gietl and his championship winning BMW AMA superbike which used a very similar setup. Aprillia has also filed a recent patent that takes this concept a little further by adding a variable ratio link in the mix to change the amount of anti dive based on how far the suspension is compressed. Interesting stuff.
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Manifolds look like the factory set up. Carb cables are cheap.
I'd bet there's some JDM car guys that would be interested in those mikuni's .
found these-
https://www.wolfcreekracing.com/index.php?option=com_content&view=article&id=69%3Amikuni-carburetor-id-guide&catid=30&Itemid=51 (https://www.wolfcreekracing.com/index.php?option=com_content&view=article&id=69%3Amikuni-carburetor-id-guide&catid=30&Itemid=51)
https://rmcarburetors.net/ (https://rmcarburetors.net/)
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Manifolds look like the factory set up. Carb cables are cheap.
I'd bet there's some JDM car guys that would be interested in those mikuni's .
found these-
https://www.wolfcreekracing.com/index.php?option=com_content&view=article&id=69%3Amikuni-carburetor-id-guide&catid=30&Itemid=51 (https://www.wolfcreekracing.com/index.php?option=com_content&view=article&id=69%3Amikuni-carburetor-id-guide&catid=30&Itemid=51)
https://rmcarburetors.net/ (https://rmcarburetors.net/)
Thanks. Looking at those sites they feature the PHH 40/44 carbs. The PHH 36 is a physically smaller carb than the more popular 40/44 that was a drop in to the Weber DCOE. It looks like the PHH 36 was a Mikuni development based on the Solex PHH 35 carb found on the Lancia Fulvia and other such cars. The original Solex PHH 35 carbs go for good money, perhaps there would be some interest in the updated Mikuni version but I have a feeling prime dollars go to the originals for factory correct parts. I also found some info about a kit being offers for Honda 750 SOHC engines that used twin PHH 36s. I will clean up the one taken off the bike and see what kind of market there is for a pair.
Inspected the brake rotors and found pitting and some separation. Too bad, would have been cool to be able to use them. Anyone know what the stock bolt circle is front and back? Perhaps I can just get new steel rotors to bolt on.
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(https://i.ibb.co/ZdFsrrH/wheels.jpg) (https://ibb.co/ZdFsrrH)
If you are looking for custom discs, I highly recommend ISR. Acke mad me a set of custom carriers for 300mm discs (this wheel was not meant for a guzzi) The cost was comparable to what EBC charges and the quality is top notch. He will make you pretty much anything. He may even take your existing carries and install new discs.
https://www.isrbrakes.se/ (https://www.isrbrakes.se/)
https://www.isrbrakes.se/order/isr_discorderingform.pdf (https://www.isrbrakes.se/order/isr_discorderingform.pdf)
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I will keep them in mind. First though I need to see if the magnesium wheels are usable. I sent an email to Magni asking for any advice on reconditioning an older set of EPM magnesium wheels but have not got a response. I wrote them in english so perhaps it was automatically ignored. First step will be removing tires, bead blasting, then testing. All this I will need to figure out still. If the EPM wheels end up being wall art then back to stock I think and then figuring out if the brake setup will work with stock wheels.
What does the stock rear brake mounting look like? The swing arm on my bike is chromed and I am wondering if/how much it was modified.
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There should be a small tab on the inside of the swing arm for the factory brake bracket.
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No small tab on my swing arm. I think the prior owner shaved it off and chromed the swing arm. It seems like this was something he liked to do as the final drive and valve covers are missing the little ribs/fins/logos that I see cast in the stock parts and are chromed as well.
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You won't be able to run the stock swing arm brake/spacer plate without that tab. The tab keeps it from moving around. It also looks like the disc brake tabs have been shaved off of the front forks.
(https://i.ebayimg.com/00/s/MFgyMTQ3NDgzNjQ3/z/KF4AAMXQ9MVRgKXI/$_61.JPG)
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On EV’s the rear brake nub is a special bolt with the threads at the head end but not at the other end which is run through a threaded hole in the swingarm to intersect with the slot in the caliper mount. I don’t know if that would be a repair option or not.
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What I am thinking now is that if the EPM wheels end up being usable I will run a anchor rod from the rear brake that is on the bike now to some point on the frame below where the swing arm mounts and only keep the front anti dive setup. This will also probably mean keeping the brakes de-linked as well. If the EPM wheels are not usable then back to a stock setup for wheels and rear brake and put it back to a linked setup as Moto Guzzi intended. The front anti dive might need to go as well depending on how much effort it is to use it with the stock wheels, my preference though would be to keep it so the bike retains some of it's personality.
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you may have to replace the fork lower legs as well, as the tabs look like they've been shaved off. (hope not)
The rear drive rod looks odd being attached to the upper frame. You might be able to rotate it 270 degrees clockwise so it's underslung and weld on an attach point to the swing arm or lower frame.
(https://4.bp.blogspot.com/_hHFW8n7lY2U/TIJvHe9aB4I/AAAAAAAAAEU/qCkBgIPjtQE/s1600/04062010167.jpg)
I hope the wheels are good, as it would be the path of least resistance.
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No caliper mounts on the fork lowers so I would need to find some new ones if I went back to the stock setup.
This bike will be a project for sure, the prior owner really changed a lot of things. Looking at the wiring harness there are a number of extra switches wired in along with an aftermarket regulator branded as Voltpak. Buried in the parts is a hand drawn electrical schematic. Don't think I will bother figuring out what was changed and just go back to stock.
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Wiring isn't a big deal. Greg Bender sells harnesses. https://www.thisoldtractor.com/moto_guzzi.html (https://www.thisoldtractor.com/moto_guzzi.html) Good guy and his stuff is top notch.
I think the brake set up and wheel set up is pretty cool. If it's not your thing, fork legs and parts show up on E-bay. You may also want to contact Mark Etheridge at Moto Guzzi Classics. (http://www.motoguzziclassics.com/)
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Do you plan on bringing this bike back to CX stock condition? Do you have the stock upper fairing as I didn't see that in the box of parts.
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Do you plan on bringing this bike back to CX stock condition? Do you have the stock upper fairing as I didn't see that in the box of parts.
I do have the stock upper fairing along with 2 windshields. Not sure yet if I will use it, depends on if the EPM wheels and the anti dive brake setup are usable. If they are I think I will use something different for the fairing like on the MK1 Lemans or a period style frame mounted fairing to keep more with the modified 80s track bike back on the street vibe. If those parts are not usable then I think I will go mostly stock and put the original fairing back on.
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I do have the stock upper fairing along with 2 windshields. Not sure yet if I will use it, depends on if the EPM wheels and the anti dive brake setup are usable. If they are I think I will use something different for the fairing like on the MK1 Lemans or a period style frame mounted fairing to keep more with the modified 80s track bike back on the street vibe. If those parts are not usable then I think I will go mostly stock and put the original fairing back on.
Do you have an H shaped piece in the pile of parts? You will need that part to attach the stock front fairing and if you do have one it would be wise to weld up a new stronger piece because mine would break after a few years of use. And if you do go with LM I front fairing you will need to open up the cut outs for the wider forks on the CX. I’ve never got the fairing to sit the same way as a the one on my Lemans I but when I can locate the LM I left headlight bracket it might solve the problem.
My CX:
(https://i.ibb.co/sbYkBnQ/IMG-0472.jpg)
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My CX:
(https://i.ibb.co/sbYkBnQ/IMG-0472.jpg)
That is one beautiful bike :bow:
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That is one beautiful bike :bow:
Thanks but it looks better in the photo than in person. I recently had the frame powder coated and a new wiring harness installed but the tank,fenders and side panels all need new paint as it’s been at least 15-20 years since they have been painted and it was used as a commuter for many years.
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Do you have an H shaped piece in the pile of parts? You will need that part to attach the stock front fairing and if you do have one it would be wise to weld up a new stronger piece because mine would break after a few years of use. And if you do go with LM I front fairing you will need to open up the cut outs for the wider forks on the CX. I’ve never got the fairing to sit the same way as a the one on my Lemans I but when I can locate the LM I left headlight bracket it might solve the problem.
I have that bracket. Where does it break?
Thanks but it looks better in the photo than in person. I recently had the frame powder coated and a new wiring harness installed but the tank,fenders and side panels all need new paint as it’s been at least 15-20 years since they have been painted and it was used as a commuter for many years.
It does look good in the photo and my guess is pretty good in person even if it is a bit worn. I always like a bike that looks like it gets used over one that is just for show. What dash is that?
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I have that bracket. Where does it break?
It does look good in the photo and my guess is pretty good in person even if it is a bit worn. I always like a bike that looks like it gets used over one that is just for show. What dash is that?
From memory it usually snapped at the bolt holes. The dash is for a 850T3,etc. https://www.mgcycle.com/index.php?main_page=product_info&cPath=276&products_id=4480
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Any updates on your bike?
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(https://i.ibb.co/wyqyhZ8/66.jpg) (https://ibb.co/wyqyhZ8)
Good luck on your project. I've enjoyed this one for 35 years :thumb:
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I'll bet that's a whole different front end - triples, tubes, axle, and of course wheel.
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Any updates on your bike?
No updates yet. This is one of those projects that just fell into my lap. I need to finish up my BMW R65LS plus some other small non motorcycle projects before I start really tearing into it.
I am more convinced though that this bike really does have only 25 miles on it. Nothing shows any signs of wear, no stone chips. foot peg rubber perfect, no carbon buildup in the exhaust etc. Talking a bit more to the original owner's daughter she only remembers this bike coming home then being taken apart. Her Dad had other completed bikes though, all modified. Sadly this project stalled when his friend who he worked on all this with passed away. This Guzzi has been just sitting in the garage for 40 years before I wheeled it over into my garage.
So much of the bike has been modified though that even if I put it back to stock I would never suggest that it is an original CX100 with 25 miles on it. Kind of the Ship of Theseus problem. I am also the type of person who believes things should be used and well cared for rather than just sit as a static display.
Wish I could find some more info about the front end, it's cool and the fabrication looks quality but I don't know if this setup has been tested on another Guzzi before or it's a one off that has never seen use. The brakes were also delinked with a different master cylinder setup on the rear but still with the stock one up front.
Once I really get rolling on this project I will start a thread in the Bike Builds section of the forum.
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The R65LS was a bigger hit with journalists than buyers, and did not stay in production for long. Today, like with most bikes that were slow selling when new, it is the 650 BMW people want. Is your red or silver?
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Mine is silver. I wanted one ever since I saw them when new. A nice survivor with 23K miles that got regular oil changes but nothing else. I mean it even had brake hoses date coded 1981. So I have been going through it and refreshing/rebuilding what needs to be and doing the bigger maintenance items. Surprised it ran as well as it did when I got it considering how much rust and crud was in the tank. Goal is to just make it a nice rider and enjoy.
(https://i.ibb.co/199vwst/PXL-20240116-012006090.jpg) (https://ibb.co/199vwst)
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Beautiful bike. I just picked up a highly modified 1980 CX100 this summer and we are still getting to know each other. Redone electrical, carbs, suspension, wheels, handle bars, Lots of COOOL stuff.
I finally got the proper side panel decals on and a Corbin seat.
(https://i.ibb.co/YXvgVL2/IMG-0010.jpg) (https://ibb.co/YXvgVL2)