Well I think I finally found a suitable project a 78 t3

[benebob]

After recovering a few years from the bad taste my 16 v7 left in my mouth and a far too ambitions first guzzi rebuild to start with in a v700 I drug this old gal home (a 78 t3) this past week.  Judging by the tires I doubt it has done much road duty for 25 years or so but it she does run, go and stop (though I wanna at least check the barrels before doing any of that stuff and do plan on replacing 'em as soon as I get everything else up to snuff. 

I know I will be in the market for at least the following parts wise.  The front turn signals and bracket as apparently they don't mount to the ears.  Headlight bucket, taillight and turns and maybe some more correct silencers. 

In the meantime I got tires on order, and will order all the bits to do a full fluid change this week.  Plenty to of things to do while I wait for parts on the other project that appeared in the trailer this month a 48 Norton es2.

I do have one question to start with.  The switch gear is pretty bastardized.  The left switch has wires soldered to the switch, the right is non existent, no keyed ignition and a push button for the starter.  I would like to go with a japanese or maybe a modern triumph switch set up.  Are there any that are more suited to an 850i then others?

[Antietam Classic Cycle]

Your front forks (at least the sliders) are later, probably from an SP. The front fender would have been a stainless one with braces mounting it to the fork.

The signals did mount to the headlight/ears originally. What's wrong with your headlight bucket? Perhaps it's just missing the thick rubber seal between the rim and bucket?

I have a pair of nice original mufflers (and header pipes as well).

Greg Bender sells a few different switches - vintage Yamaha style and modern Domino. I've been using K&S switches on my Convert and have a few spares of those.
https://www.thisoldtractor.com/for_sale_wiring_harness_tonti_850_t3.html
K&S switches:
https://www.mgcycle.com/index.php?main_page=product_info&cPath=37_140&products_id=183
https://www.mgcycle.com/index.php?main_page=product_info&cPath=37_140&products_id=2592

I'll be parting out a '76 850-T3 if there's anything else you need.

[benebob]

Good catch eagle eye Charlie on the forks and fender which is plastic.  I suspect the ears may be of an sp as well as no holes.

Headlight doesn't fit well and is slightly bent.  Haven't pulled it to look yet plus the bucket has some poor repairs. 

Yeah that complete exhaust may be up my alley.  Will need rear pegs as well at the very least so far.

Would love to find a period correct switch set that lets me turn the lights off  if I can.   

Got the bits on the way to do a full fluid change probably first since Ollie was selling guns to Iran.  she does run rather well though all things considering. 

Your front forks (at least the sliders) are later, probably from an SP. The front fender would have been a stainless one with braces mounting it to the fork.

The signals did mount to the headlight/ears originally. What's wrong with your headlight bucket? Perhaps it's just missing the thick rubber seal between the rim and bucket?

I have a pair of nice original mufflers (and header pipes as well).

Greg Bender sells a few different switches - vintage Yamaha style and modern Domino. I've been using K&S switches on my Convert and have a few spares of those.
https://www.thisoldtractor.com/for_sale_wiring_harness_tonti_850_t3.html
K&S switches:
https://www.mgcycle.com/index.php?main_page=product_info&cPath=37_140&products_id=183
https://www.mgcycle.com/index.php?main_page=product_info&cPath=37_140&products_id=2592

I'll be parting out a '76 850-T3 if there's anything else you need.

[Antietam Classic Cycle]

Good catch eagle eye Charlie on the forks and fender which is plastic.  I suspect the ears may be of an sp as well as no holes.

Headlight doesn't fit well and is slightly bent.  Haven't pulled it to look yet plus the bucket has some poor repairs. 

Yeah that complete exhaust may be up my alley.  Will need rear pegs as well at the very least so far.

Would love to find a period correct switch set that lets me turn the lights off  if I can.   

Got the bits on the way to do a full fluid change probably first since Ollie was selling guns to Iran.  she does run rather well though all things considering.

The signal stalks thread into the headlight shell at the mounting bolt holes.

I have a NOS headlight, but It's worth as much as some complete bikes.  Mark @ Moto Guzzi Classics might have a good bucket. I think I sold my last good one.

Greg Bender sells a replica of the '70s Yamaha switch, and there are repros for Kawasaki Z1s available as well. Not terribly difficult to wire in.

I don't have a crossover (already sold that) but do have header pipes and mufflers. 

[benebob]

Okay first dumb series of questions. Having read the clymer 850 section on forks i am confused as to what needs to be done to do a fluid swap as it seems they want ya to disassemble the whole
Fork and 1/2 the front end. To drain and refill
I just need to remove the hex bolt on the center on the top guessing 32mm nut then take the 32mm nut off turn upside down to drain then refill?  As Charlie said these are probably sp forks
Do they get atf as well and how much should each get?

[Antietam Classic Cycle]

There's a drain screw (originally an "allen"/socket head) down at the bottom. To refill, I put a jack under the sump (with wood to protect the fins), unscrew the bolt holding the damper to the top plug (M8), raise the front end a little - forks should extend - dampers drop out of the top plug. >OR< leave the M8 bolt in, unscrew the top plug from the fork tube (helps if the top triple pinch bolt is loosened), lower the jack until there's a gap between the fork tube and bottom of the top plug enough to pour oil into. Measure the correct amount of atf and refill. One of those pointy tips from a gear oil bottle makes a good mini-funnel.

The spec. for SP forks is 40 cc each leg, but 850-T is 50 cc and T3 is 60 cc. It's only for lubrication.

[benebob]

All fluids aside from brake fluid has been changed but I do have some dot 3 waiting for some new pads to arrive to do that.  Spent today going over some electrics.  Seems I can get just about everything to work minus the tail light wiring.  Can't seem to find a T3 us wiring diagram but from looking at the euro wiring diagram and an online 74 usa t diagram I am assuming that the red wire going to the rear is for the tail light and the yellow is the  brake light.   There is a larger gauge black wire as well which from the 74 diagram appears to be for the plate light but that doesn't make much sense watt wise.  Also, I have two maybe 24-26 gauge black wires in the headlight bucket that I had thought might be grounds for the front turns but it doesn't appear they are grounds.  They are cut so any help on what these might have been for would be a big help.  Finally the fuse box is missing the  bottom fuse which from what it looks like to me the bottom two fuses are spare and aren't wired to anything is that right?  If not a diagram of what each one goes to would be lovely.  Still not exactly sure what I want to do for switches as what i have though working isn't for the long term as a po wired the left switch externally 

[Antietam Classic Cycle]

Wiring diagram at page 60 of 62 here:
https://www.thisoldtractor.com/mg_manuals/owners_manual_850-t3_1975-06_en.pdf

[benebob]

Well today was the first day of an actual short ride.   Still have a wonkie oil pressure set up as the light spends very little time out and the hamdlebar switches are cobbled together but worth taking it around a country block so about 5 miles or so.  Engine ran just fine, clutch seems a little weak but could just be from decades of limited use, speedo is inop so I guess I'm gonna need to figure out how to  put on this contraption I was sent that is to be a speedo cable.  Handling, brakes bearing seem solid.  Only real ridable issue is she's got a death pogo around 45-50 mph.  Nothing til then and if you go beyond 50mph nothing above.  I'm assuming this might be dead front suspension dampeners as  the front end seems to be quite easy to compress.  That said without pulling the dampeners and measuring them is there anyway to determine if they are an 850t3 dampener or from a later sp1000 or 850t4?  Did decide to be lazy and ordered switch gear from Greg so progress is being made.   Sadly Saturday am on the way to cars and coffee my 97 Triumph Speed Triple decided it no longer needed 6 tranny gears so now I have 3 bikes  on the project side of the garage and a jeep that has a 61 year old clutch about ready to head to the willys afterlife. 

[Antietam Classic Cycle]

I've successfully refilled original dampers (if they're not leaking) and eradicating the "pogo". Basically, one drills a small hole in the top (where the M8 bolt threads in), squirts/drains all of the original Italian fish oil out, and then refills with fork oil. I can go into more detail if you're interested in doing this.

[benebob]

So you think that “pogo” even limited to about 45-50mph speeds is one or both front dampeners being empty then. Seemed a little odd to me as any slower or faster and it disappears pretty quickly. I’d figure at 50 years old i might as well just replace em as they don’t appear to be that expensive. Any method you can think to tell which forks I actually have on there?  Is the sp one longer externally by that 20mm by chance? 

Getting my parts list ready for ya for that one you are parting but doubt things will happen on that end til I get back from the greenbrier concours the first week of may. Soon gonna need to focus on getting the - prepped for that.

[Antietam Classic Cycle]

So you think that “pogo” even limited to about 45-50mph speeds is one or both front dampeners being empty then. Seemed a little odd to me as any slower or faster and it disappears pretty quickly. I’d figure at 50 years old i might as well just replace em as they don’t appear to be that expensive. Any method you can think to tell which forks I actually have on there?  Is the sp one longer externally by that 20mm by chance? 

Getting my parts list ready for ya for that one you are parting but doubt things will happen on that end til I get back from the greenbrier concours the first week of may. Soon gonna need to focus on getting the - prepped for that.

My 1000SP would only "pogo" at about the same speed, on bumpy turns. Draining and refilling the dampers cured it. The dampers are never empty (if they were then that would mean they'd be leaking and I wouldn't bother refilling them), but rather the oil used is just too low viscosity to provide adequate damping after years of use.

It's hard to tell what mixture of parts you might have - it could be just the SP lowers were used with the original T3 internals, or they could be complete SP forks. I think you'll need to remove the dampers to tell.

 

[benebob]

Fork is off and dampener and spring are out.  Now  exactly how do I measure it to tell if it is a 850t3 or a sp set up.  Looking at Crusty Cycles seems they list a 395mm for the 850t3 which is roughly 15.5 inches so I would assume it is stretched out tip to tail correct, they then list the 410mm ones for the later bikes and sp as being 410 or 11.5" which of course with my math 410 comes out to be about 15.25" not 11.5.  there should be no need to remove the dampener from the springs correct as I'd like to put it all back together while I wait for the  new bit.  'Have about 100 miles on her so far so she's coming along.

If I measure it as assembled I get roughly 15.5 inches from the bottom of the female threads on the dampener up to the bottom of the nut on the male threaded side.  Just what to make sure I order the right ones.  Thanks!

[Antietam Classic Cycle]

Fork is off and dampener and spring are out.  Now  exactly how do I measure it to tell if it is a 850t3 or a sp set up.  Looking at Crusty Cycles seems they list a 395mm for the 850t3 which is roughly 15.5 inches so I would assume it is stretched out tip to tail correct, they then list the 410mm ones for the later bikes and sp as being 410 or 11.5" which of course with my math 410 comes out to be about 15.25" not 11.5.  there should be no need to remove the dampener from the springs correct as I'd like to put it all back together while I wait for the  new bit.  'Have about 100 miles on her so far so she's coming along.

If I measure it as assembled I get roughly 15.5 inches from the bottom of the female threads on the dampener up to the bottom of the nut on the male threaded side.  Just what to make sure I order the right ones.  Thanks!

410 mm = 16.14" not 15.25". MG Cycle lists the dimensions as "overall length" which to me means fully extended, body and rod. Your measured 15.5" plus however much male thread is past the nut (~ 5/8"?) makes it sound like SP dampers to me.

[benebob]

Thanks for catching my typo. Had 16.15 in my head but also had the 15.5 in there😭. So you would go with the 16.15 ones then. I like that idea as they are a couple gallons of gas cheaper.

[Antietam Classic Cycle]

Thanks for catching my typo. Had 16.15 in my head but also had the 15.5 in there😭. So you would go with the 16.15 ones then. I like that idea as they are a couple gallons of gas cheaper.

If what you're measuring is 15.5, the threads likely make up the remaining.65. The only way to find out for sure is to remove the spring and extension rod, then measure over all length full extended.