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1978 Le Mans restoration

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2WheelsUp:
Iíve 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:

--- Quote from: Canuck750 on December 01, 2021, 06:01:24 PM ---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.

--- End quote ---
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.

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