1978 Le Mans restoration

[2WheelsUp]

I’ve been lurking on this site for the last few months picking up useful tips and facts about how best to restore my 1978 Le Mans I bought a few months ago. Before jumping into my project, a bit of background since I haven't posted on this site before.  I grew up on the Western Suburbs of Chicago but now live in North Georgia. I've been riding motorcycles since my teens, started with Nortons and became a fan of Guzzis when I bought a new 78 Le Mans from Ellis at Geneva Cycle shop, a unique experience for anyone who knows him. Over 20 years I toured most of the continental US and Northern Rockies on the Le Mans.



Outside of minor issues, it never left me stranded or broke down during all the trips and miles I put on that bike. I sold it to buy a new '97 Ducati 748, which I still have, a wonderful bike but I never, ever, should have sold the Le Mans. I also have a 2001 HD RK which I love and a Ducati 939 SS which is my daily rider and awesome around the roads in N GA. I sold my Norge over the summer, had it for over 10 years, just fell out of love with it and it wasn't getting ridden, so off it went.

Back to my project... I bought the Le Mans from the second owner since 1984 with 8900 miles on it.


Based on a close inspection I believe those miles to be reasonable given it's condition. It was obvious the bike hadn't been ridden for some time but after a tune by @GuzziSteve, who is helping me with this project, it ran surprisingly good. I was able to do a couple shake down rides of about 70 miles with a few runs to around 80 mph. The problems we found are a couple oil leaks; final drive fill plug is stripped, and its leaking oil from the gearbox/engine bell housing and clutch slipping presumably from the oil. The pumpers were not working well but after some riding they seem to get better. There was a bit of smoke coming out of one exhaust but that also seem to correct itself after riding it... sticky rings? The previous owner had just changed the all the fluids to synthetic so perhaps that was causing some leaks. I changed back to standard oil before my shake down rides. The frame is fair, usual scratches, marks, but the swing-arm was rattle can painted gloss on one side with a lot overspray. Looks like a battery leak pealed the paint from the rear of the main frame and it now has surface rust on it, hence the gloss paint job on the swingarm. It had fallen at least once, top two head fins on the left side has been repaired; more like filing them down to blend in, reasonable job, not sure what else could be done short of a new head. The wheels had been painted gold... sigh. The body was fair but tired from age. Given condition of the frame, the fact the gear box had to come out, and being a 43 old bike that had been sitting for who knows how long I decided to do an extensive restoration made possible with a lot of help from @GuzziSteve. Strip and repaint the frame, re-paint the wheels, new clutch, cables, replace seals, bearings, and gaskets on the frame, forks and drive train.  Overhaul the brake system; rotors resurfaced by TruDisk, new pads, and new lines, maybe rebuild the calipers. Maybe a new wire harness... I'm talking with Gregory Bender about it now... but the old harness is pretty good so not sure yet it makes sense.  Is it worth it, is it straight forward?

Originally I was going to leave the body paint alone but that changed once I committed to all of the above so it's going to be repainted. I know there's a lot of debate about whether and how to restore vintage bikes but all my other bikes are pristine, they all are ridden regularly (no garage queens here), I'm not much of a patina guy, and I don't plan on selling this one, ever, so why not, it's for me?

We started a few weeks ago and now have the frame completely stripped and Steve is going though the drive train. 







I'm thinking we might want to pop off the heads to see the condition of the valves and cylinder walls given it was smoking a bit before the tear down.  We did a compression test (180/175) and leak down test that didn't show anything significant so perhaps I'll get lucky. I may want to look at the timing chain and tensioner... that's a bit more work.

I just had the valve covers Vapor Honed

...wow what an amazing finish. I'd love to do the engine block, cylinders, and heads but that means a lot more work, tearing down what looks to be a good motor, multiple people are telling me it's not worth it... but does that ever look good... decisions. There are two thoughts that I keep encountering... do I pre-emptively tear down things that appear to work to prevent a possibly failure later... or do I leave things along until I have a clear signal there's a problem.  Add to that .. I hopefully will never having things torn down again with this bike. I've never done this before so it's something I'm struggling with. What do you think?

Kent at GMD Computrac told me to not put the frame in an oven so it's being painted by a local guy who is doing my body work. It's also been suggested that I paint my wheels rather than powder coating due to the heat. What have you all done? Can I powder coat the wheels?

I have the PPG code for Mahindra Red Passion ... just picked up a sample, any other suggestions are welcome (e.g. MGB Flame Red?). I need to find the color codes for the florescent orange and the silver wheel color.  My painter requires PPG codes and so I need to come up with those.

One other thing... the front suspension. I have Koni's on the rear and I've reviewed my options for the front and it appears a great option would be a SD20 fork cartridge from Maxton Suspension in the UK https://www.maxtonsuspension.co.uk/files/sd20.html. Anyone know about these or try them? They look like a drop in from the measuring document they sent me, possibly some work to the fork legs but hoping it'll fit, or they make it fit, into the spring guides at the bottom of the legs. I ride all the bikes I own and am in an area with good/challenging roads so installed under $1k may be worth it.

I'll keep posting my progress, hoping to have it back on the road by early Spring.  Thanks for reading my thread, and please pass on any advice you may have. 

Cheers!
Bruce

[Groover]

Thank you for sharing this!

[Canuck750]

Nice project!

With respect to tearing down the motor, I would vote yes, regardless of what condition the engine apears to be in its over 40 years old, and every Guzzi 750 / 850 I have been through needed new valve guides at a minimum and just about every one of them (six engines in total) needed a pair of main bearings, big end shells and a crank shaft grind. Rear main crank seal, rear main bearing gasket, clutch kit etc, is most always needed. Steering head bearings, swing arm bearings and all the wheel bearings and seals are typically replaced.

[2WheelsUp]

With respect to tearing down the motor, I would vote yes, regardless of what condition the engine apears to be in its over 40 years old, and every Guzzi 750 / 850 I have been through needed new valve guides at a minimum and just about every one of them (six engines in total) needed a pair of main bearings, big end shells and a crank shaft grind. Rear main crank seal, rear main bearing gasket, clutch kit etc, is most always needed. Steering head bearings, swing arm bearings and all the wheel bearings and seals are typically replaced.

A lot of what's on your list is being done... only thing we're debating is the going through the lower end given the low miles. That said, once we have the head off and dissembled, how do I know if the valve guides need replacing?

Another topic... I noticed you powder coated your wheels. I've been warned against that for older wheels due to the heat required to coat them. Should I have concerns powder coating my Le Mans wheels?

[Canuck750]

I would take the heads to a machine shop and ask them to inspect the guides and at a minimum cut the valves and seats.
Powder is cured between 350 and 400 F, no problem for aluminum or steel.

[berniebee]

Looking forward to seeing progress on the bike!

Regarding the wire harness, the first thing to keep in mind is that they were never designed to last that long. Have a look at the spade connectors in the fuse box area and the other connectors under the backbone and at the headlight. Especially if the bike has spent any time in a damp location, you'll see the green corrosion. That corrosion usually makes it's way up along the wires, under the insulation.  Flex some wires and see if the insulation is brittle or cracking. If there are any questionable bits, just replace the entire harness while you have the bike apart. For lighting, the minimum you should do is remove and reinstall each bulb in order to scrape off some of the 40 plus years of corrosion on the connectors.

My '83SP electricals didn't look too bad at first glance, but the deeper I dug...well, I rewired the whole dang thing.

[Scout63]

Once the engine is out, gearbox and clutch removal are pretty straightforward.  I would go all the way and pull the crank, vapor hone the crankcase and gearbox, and renew all oil seals and gaskets.  They are 40+ years old.  I did this for my G5 and it was a very rewarding experience.  It’s sitting next to my non vapor honed SP and the difference in the look is significant. I’d also install new harnesses as they would be your problem area in the future. Great project and great story. Ben

[Antietam Classic Cycle]

https://www.thisoldtractor.com/for_sale_wiring_harness_tonti_le_mans.html

[2WheelsUp]

Thanks for the feed back.  Wire harness is a good idea even though mine appears to be in great shape, don't want to chase electrical problems.  I'm pulling the front cover and installing a new timing chain, auto tensioner, and new rotor/brushes.

On another topic... I don't want to powder coat the frame as per Kent @ GMD Computrac's recommendation. My painter suggested PPG Ditzler Hot Rod Black https://us.ppgrefinish.com/PPG-Refinish/Product-Annoucements/Ditzler-Hot-Rod-Black-Kit . It's a multi-part single stage Acrylic Urethane topcoat applied over a primer. I was planning on using it for all the black bits... the frame, swing-arm, foot controls, triple trees, headlight bucket/lens and the clip-ons. It claims to be a satin finish but I haven't been able to find any samples since it's a kit and the PPG stores can't mix it so I'm a bit concerned that I won't see it before it's being laid down but I'm thinking we'll do a sample and see if it's ok before proceeding, worse case we toss it if we have to and move on to plan b. There are other kit's like this from SEM and Eastwood that might have a bit more gloss to them.

Related note... I removed my VIN plate in preparation for frame painting by using a curved head bolt along with a coupler nut that you stick into the neck and expand by unscrewing the nut. Worked perfectly... the drive screws look like new but MG Cycle has replacements I'll use.

Question for those who have had their wheels recoated.  My rear wheel is disassembled except for the sleeve that is pressed into the wheel. Do I need to remove this before powder coating and/or before chemically stripping the paint on the wheel?  If so, does this need to be pressed out by a machine shop or is it something I can do?

[Canuck750]

I believe the Le Mans frame paint was a low gloss, almost flat black, not the same as the typical Guzzi Tonto frame semi gloss black. I think the chassis paint you are referring to may have a higher sheen than the original LeMans finish.

I have always gone for powder coating of the frame and related chassis parts but on my 1948 Airone I had all the chassis parts painted with single stage enamel and will finish the tin parts with base coat and clear over the pins stripes and decals. What I have found working with the enamel paint (it has been curing for a couple months) is that it chips much easier than powder coat. Assembling wheel bubs, break drums, etc on the Airone I am having to be very careful to not knock a part or it chips. Now I can touch up the enamel but I could just a easily touch up the powder cured finish with a matching enamel paint. I have found the powder coated frames to be much more durable, my 72 Eldorado had been on the road for eight years now and hardly a mark on it, same for my 75 Ducati after a coup0le summers riding. It is vital to use a powder coater who is experienced with coating motorcycle frames, that will bake out an oils, prewash the frame and be light around stampings etc.

just my two cents.

[2WheelsUp]

Ok so I've decided to powder coat the frame after all... now just need to choose the powder.  The frame is stripped and hole for the pins are blocked but do I need to block off all frame holes, just threaded holes, or don't worry about it? 

I'm planning on powder coating the headlight bucket, lens, and the ears.  Should these more delicate parts be chemically stripped rather than sand blasted before coating?

[Canuck750]

Ok so I've decided to powder coat the frame after all... now just need to choose the powder.  The frame is stripped and hole for the pins are blocked but do I need to block off all frame holes, just threaded holes, or don't worry about it? 

I'm planning on powder coating the headlight bucket, lens, and the ears.  Should these more delicate parts be chemically stripped rather than sand blasted before coating?

The powder coater I use specializes in automotive and motorcycle work, he also does commercial work but understands the expectaions of customers completing a restoration. The shop I use does all their own blasting, preheating, cleaning etc, and they take care of blanking off all holes, bearing surface etc. Doing your own prep requires a lot of work to get the base material properly cleaned and prepped, I use my vapour blaster and acetone wash for the small parts I powder coat in my shop with an old wall oven, I also use metal prep wash to treat the fresh blasted surface before any surface rust starts. I would make sure the coater shop you plan on using is familiar with motorcycle restorations, that they do their own blasting, metal prep and they bake out any residue grease and oil in the oven before coating.
Sand blast is too aggressive for this kind of work, at most I would use a fine glass bead or a soda blast.

this is a picture of the matte black powder i used on my 77 Le Mans restoration

[2WheelsUp]

Thanks for the info. I'm heading over the powder coater tomorrow to see his shop. He does a lot of motorcycles but not sure how he preps them.  We'll see...

[Motorad64]

Great project, 2Wheels! 

I did the same thing to years ago. I generally prefer paint on frames, as well but went with powder coating after seeing a few of Charlie’s projects by a local vendor.  I did, however go with paint on the wheels to preserve the raw aluminum edge of the rim and the little M-G eagles.  The painter clearcoated the whole wheel over the silver for the centers.  I did not press out the sleeve but cleaned it aggressively with scotch bright and sandpaper.  Probably due for a seasonal greasing now that I’m thinking g about it.

[Motorad64]

Meant to add...I did the FAC dampers/Wirth progressive springs for the fork rebuild, but would LOVE to hear your results on the Maxton option.  Was considering that myself.   The FACs took a bit to break in but still don't offer a ton of compliance.  Lotta stiction but not sure thats the cartridge vs overal fork.   I did Bilstein rear shocks from HMB and have been very happy with them.  May go the Maxton route next year.

Once you vapor or bead blast one component you kind of have to do it all, but its worth it.  Looks great and should be easier to keep clean.  My wiring also looked intact but was pretty crispy.   The Greg Bender harnesses are great and he's super helpful to work with on any issues you run into.  I had the same likely battery acid damage and overspray on my swingarm, as well. 

[2WheelsUp]

Once you vapor or bead blast one component you kind of have to do it all, but its worth it.

I know... did you vapor or bead (shot peen?) your cases? Can you share a link to more pictures of the engine/gearbox or perhaps send me a PM?  Also, I like your rotors... who makes them?

[2WheelsUp]

I found your project thread Motorad64... really nice build. I can only hope mine will approach what you, canuck750, and Dave, and others have done... inspiring! I'll keep digging into previous builds... good late night geek reading

I found a good powder coater in the ATL area... he does a lot of bikes for local builders... we'll see in a few weeks


I picked up a set of clip-ons to replace the bent one that came with my bike. They are in great condition except they are chrome rather that black as is proper with a 78 LM1. I'm sure the chrome version will look great on my bike but I'm leaning toward de-chroming it and sending it along to the PC. I know plating services can de-plate chrome... looking into that now... but are there other ways to do it correctly?

 

[1down5up]

The black clips ons were black zinc, not paint (or powder coat). If you are using the original switch gear it earth's through a foil tab on the back of the switched onto the clip ons, paint or powercoat will result in your switch gear not working.

If your not using the original switch gear won't be an issue though. Just make sure the powercoat is t to thick so you can still fit the clutch perch and front master cylinder on

[Motorad64]

It seems like some of the early ones had chrome headlight ears and bars.  My '78 had black painted headlight ears and black painted bars.

On your thoughts whether to rebuild motor/trans...I decided to have someone more experienced open it up and check everything out.   No idea of the bikes real history, a welded up oil sump drain hole and just 40yr old seals, etc made me want to go ahead an invest in the rebuild.  That way I could ride the crap out it with a clear conscience knowing its true condition

[blackcat]

I kept the original switches and went with Greg Bender’s relays as per his suggestion just to make sure none of the wires and switches get fried.



Those switches are very expensive nowadays so the $92 bucks spent on the relays will possibly save money in the long run.

I also powder coated the frame and wheels and I had the engine,transmission and final drive all vapor blasted but on another Guzzi projected I had the same parts soda blasted because everything was rebuilt and the soda is not a problem compared to the vapor medium. But the vapor finish is better.

[Canuck750]

Glad to hear you are opening up the bottom end and transmission. Hopefully previous owners kept up with oil and filter changes and you can avoid a crank grind.

[acguzzi]

I have maxton in my forks, I love them, but they wouldn't ship to the states, I had to have them shipped to my father in UK and then have him ship them here. PIA

[Antietam Classic Cycle]

I have maxton in my forks, I love them, but they wouldn't ship to the states, I had to have them shipped to my father in UK and then have him ship them here. PIA

A friend in New York bought Maxton dampers and springs from this company:
http://www.e-nproducts.com/dealers.php

[2WheelsUp]

Thanks for the feedback. I'm in contact with the folks at Maxton as of a couple months ago, they will ship to the US. They are recommending their SD20 cartridge at around $750 for the pair



They sent me spec sheet that I need to fill out with dimensions of my existing Le Mans forks.



They mentioned there may be some machining required to the fork legs to allow the base of the damper cartridge to sit in the bottom of the leg. I'm not sure that will be required given the measurements I've taken compared to what they provided me. I'm hoping the end of the SD20 damper will fit snugly into the existing LM1 damper rod seat which is positioned at the bottom of the leg. Given they have already produced sets for other LM1's I'm going to ask them if they have those specs rather than risk me sending them a bad measurement. For the money it's a pretty good deal compared to modern sport  bike suspensions... heck I paid close to that for a Matris shock on my Norge.

Acguzzi what bike did you put the Maxtons on?

[Motorad64]

Really hoping you pull the trigger on these...;)   I may be right behind you. 

[2WheelsUp]

For those who have powder coated their frames, should a clear powder coat be added after the base coat?  The powder coater told me no but I've heard from friends who did do this to protect against staining and UV protection.

[Canuck750]

Applying a clear top coat is usually not very expensive and I typically apply a clear of the same sheen as the base coat. If your parts are pitted a powder primer coat(a) can be applied and sanded prior to the colour coat. I have started using powder primers as they are like a very heavy filler primer but being electrostatic applied the primer makes a great sealer. The primer sands very nicely with a 240 grit, no need for finer sanding as the powder cure will fill 240 scuffing.

[Antietam Classic Cycle]

For those who have powder coated their frames, should a clear powder coat be added after the base coat?  The powder coater told me no but I've heard from friends who did do this to protect against staining and UV protection.

I've never found it to be necessary. One of the first frames I had powdercoated was for a customer's Eldo. That Eldo sits out in the sun a lot, is ridden through fields (owner is a commercial vegetable farmer) and is never washed. When it comes here each Spring for it's annual service, I clean it a little and the frame still looks great - no fading or discoloration.

[2WheelsUp]

As always, thanks for the feedback guys! 

[huub]

you might consider fitting cartridges from a nineties showa fork
i have honda RC36 cartridges in my le mans 2, I got a cheap set of used forks on ebay.
the cartridges  transformed the handling of the le mans , and i can play around with shims and oil viscosity to fine tune them ( they did not need it) .
you will need a lathe to cut new threads on the fork tops , but even if you have to outsource that , it will still be a lot cheaper.
you might safe enough money to buy a proper set of rear shocks , the koni's are seventies technology, they were adequate when new.
by now they are hopelessly outdated.
 
you can rebuild them or have them rebuilt, i did quite a few of those in the time.
just dont expect too much.