750 S3 - the recommisioning

[canuck750]

Last year I took over custody of a fine 1975 Moto Guzzi 750 S3. Its previous guardian was Luca from Toronto. Luca cared for this rare beast for over 30 years, brought it with him across the ocean from London over three decades ago and took very good care of it. Luca was gracious enough to pass the care and feeding of the S3 on to me with the knowledge that it would be loved and cared for.








Other projects are done so its time to start on the rebuilding of the S3. The paint on the tank is pretty nice for a 40 year old machine and most of the rest of the bike is in good shape for a machine that was regularly ridden. I am going to take it to a pro to see if it can be colour sanded and polished, perhaps clear coated to preserve it,



I have been taking stock of the bike for the past 6 months deciding what to do with it. I won't paint the tank or side covers but I am going to repaint the frame, swing arm and side stand. The triple clamps will be repainted, same with the instrument support.

Chrome bits are pretty good but they are pitted and showing their age, all of the chrome parts will be sent off for replating.



Rubber parts are about done, I will replace all of the rubber items,



I will order a complete wire harness set from Greg Bender



strip the wheels, check the rims, polish the spokes, and replace the tubes and tires



I stripped the brakes a month ago, rebuilt the calipers and had True Disc regrind the rotors, I am slowly powder coating the rotors, new hoses and steel lines have been sourced. New wheel bearings, steering bearings and swing arm bearings will go in.

I will replace or clean up all of the misc electrical bits





I found a pair of NOS pistons and rings so I have decided to send the jugs to Millenium for coating, and the heads will get rebuilt. I will pull the crank, check the bearings, get the rods balanced, check the timing chain and fit new seals and gaskets.

I will pull the transmission and rear drive out and check the bearings, shim the shift drum and replace the seals and gaskets.



I found four NOS Aprilli signal lights to replace the pitted originals.



I found a pair of original shark gill mufflers and had them ceramic coated matte black,



The fork tubes will get replaced and new springs, FAC dampers, seals and dust covers installed.

Plenty more to figure out.

Should be fun, a year of scrubbing, polishing, plating and painting should set it right. :BEER:

[EldoMike]

Sweet bike, looking forward to your progress.. ;-T

[Vasco DG]

S3's are lovely. Don't 'Over-Restore' it, it has a nice patina of age.

Pete

[Chuck in Indiana]

Go for a ride. Winter in Canukistan will be here in another 3 months or so.. ~; :BEER: Do the rehab then so I can watch.  ;D

[smdl]

Looking forward to following your progress, Jim!  I was discussing with Luca a couple of weeks ago, and I know he will be following with interest!

Cheers,
Shaun

[750S3]

Following the restoration of the old girl with keen interest. You can tell her her big brother (Griso Tenni 8V) says hi.
We knew it went to a good home. Thanks Jim.
Luca

[nick949]

Following the restoration of the old girl with keen interest. You can tell her her big brother (Griso Tenni 8V) says hi.
We knew it went to a good home. Thanks Jim.
Luca

 ;-T

Nick

[Motosan]

Jealous! I wish there were more of these in the world.

[canuck750]

Following the restoration of the old girl with keen interest. You can tell her her big brother (Griso Tenni 8V) says hi.
We knew it went to a good home. Thanks Jim.
Luca

Hi Luca, sounds like you got a fine replacement with the Grisso ;-T

The Black V7 Sport gets picked up by the shipper this afternoon, there will be open floor space again in the garage so its on to the lift for the 750S3 and off with its bits and pieces!

Cheers

Jim

[Cam3512]

I know it will be tough for you, but resist doing too much cosmetic work.  I like the original patina.  It's a slippery slope, the more you "restore", the harder is is to stop.  Next thing you know you'll be painting the tins!

Perfect bike not to sweat the chips or the weather.

[jbell]

Nice looking bike, Jim.  My favorite Guzzi.  Thanks, again, for your help with my project.  I've passed the favor on to another member with some stuff I've been hauling around for 40 years or so...........Jack. 

[canuck750]

I know it will be tough for you, but resist doing too much cosmetic work. 

Tough is an understatement.... I scored an amazing find last week on German Ebay - a matching pair of like new 750 S3 black and orange side covers! The originals that came with the bike will be wrapped up put away for safe keeping.

I absolutely promise to not paint the tank!

As for the rest, I don't think I can help myself, I was hoping I could leave the frame alone with its nicks, chips and surface rust, I just can't :(.

I am going to investigate getting it sprayed rather than powder coated to stick with original type finish.

The thing is once I finish restoring a bike I have no issues riding it in any conditions, I can always restore it again, no trailer queens here. :BEER:

[Stevex]

There's patina and there's patina; looking at your pics, that bike's crying out for some serious tlc.
Paint work looks great, as you say, for a 40 year old, but as for the rest, I'm with you...

As for the rest, I don't think I can help myself, I was hoping I could leave the frame alone with its nicks, chips and surface rust, I just can't

I went down the powder coat route with the LM2, it's the one regret I have. Wish I'd stuck to satin black paint finish for the frame and brackets etc.

[canuck750]

My method to restoration is to take one assembly off at a time, rebuild and refinish it and then put it away until I am ready to reinstall it. The first major group of parts to come off were the brakes; calipers, rotors, master cylinders and hoses.

The rotors went off to True Disk to be reground, fantastic service, $45 a rotor. I then powder coated the black centres of the rotors. A new set of mounting bolts were sourced from MG Cycle.



The caliper bodies were saved but everything else was done, one piston in each caliper was seized, two seized bleeders and the seals were leaking.



I stripped the caliper bodies and powder coated them, then fitted all new parts including the upgraded anodized pistons.



Like new now



The front master cylinder body was very heavily pitied,



I bought a better one from Mark Ethridge, I stripped it and powder coated it. Fitted a new piston kit, should be good to go.



The rear master cylinder was pretty much done as well, corrosion on the cylinder.



The cast cylinder is in pretty bad shape, not sure I am going to trust it but I cleaned it up in any event and installed a piston kit, I think I am going to fit a new one on the back as it is hidden behind the side cover and I would rather be safe than accurate ( new replacement MC are a little different cosmetically).

HMB is sending me all new steel lines and I found a set of black replacement brakes hoses from them as well.

So that about takes care of the brakes, boxed up and put away until I am ready to reinstall them.

A box of carb parts came in the mail today do I think I will remove the carbs next.

[racasey]

The rotors went off to True Disk to be reground, fantastic service, $45 a rotor. I then powder coated the black centres of the rotors. A new set of mounting bolts were sourced from MG Cycle.

Hi Jim, I have a question about the brake rotors.  I have found that when powder coating parts, powder will be thicker on edges, particularly lower edges, due to gravity.  Powder on surfaces like the mounting surfaces of a brake disc may no longer be of uniform thickness, resulting in a disc that now may show wobble or run-out.

How do you deal with this situation?

Thank you for starting another  project.  Your beautiful work and excellent reporting proved much pleasure to this reader.

Ciao,
Dick Casey

[canuck750]

I think you raise a good point Dick, unfortunately I don't have an answer on how or if the powder coat may impact balance, honestly never considered it. The rotors were hung flat to bake so it may negate any localizing of powder build up to one section. No idea how to measure for balance. Hopefully I have not effected the performance.

Cheers
Jim

[JJ]

Congratulations!  That's one fabulous (...and RARE) model Guzzi!  Restore it, sort it, ride it, and most of all enjoy it!  She deserves to be ridden and "In The Wind" again! 8) ;-T :)

[canuck750]

A day out of the office and quality garage time. Today he carbs came off and were stripped.



Then 2 hours in the ultrasonic cleaner with ultrasonic cleaning solution

Comes out like this, super clean, and new fasteners, needles, O rings, gaskets, and springs



Then just put it back together

I fit new springs when I build these VHBs'



The floats were set at 25mm, I think that's correct



My Wife bought me some small dental tools for fine work, this needle pick is perfect for getting the tiny O rings off



I use the double banjo fuel line fittings and ditch the Guzzi cross over



Delicate little choke O ring



And they are done, the ultrasonic solution does a fine job of cleaning up the castings without any soda blasting
I have resisted polishing the castings and finish them like they came out of the factory



While the Ultrasonic cleaner was doing its magic I stripped all of the wpre harness components, electrical and exhaust









Curious to see what the heads and cylinders look like

[canuck750]

Pulled the heads and cylinders this morning





No big surprises but the cylinders are flaking as suspected



Harpers supplied a pair of NS pistons and rings so I am going to save the original cylinders and send them off to be re-plated

MG supplied valves, springs and guides



After I strip the heads and soda blast them they will go to a machine shop to cut the valves seats

Lifters look good, push rods are straight, but the rocker pins show a lot of wear at the top half on all four, I think a set of new ones are in order.

Next to pull the engine and transmission out

[smdl]

 :pop

[canuck750]

Got a little more done in the cleaning and prep of the heads and cylinders, it was off to the car wash with a 50/50 solution of water and NAPA Aluminum Brightener in a spray bottle. Several soakings later and a quick blast with the high pressure wand an inch off the casting and they come clean



Then back in the lane after the parts thoroughly dried a quick going over with a soda blast and the remnant of oxidation and the carbon in the head exhaust tracts are gone.



If you have never used a soda blaster it is amazing, all you needs is a 5 gallon pail of soda and a siphon spray gun from Harbour Freight, as the soda particle hits the part it explodes and knocks the detritus off the surface instantly.

These rocker covers were still discoloured after chemical washing, a pass over of the soda and like new



The heads go to the machine shop this week and the cylinders and new pistons/ rings off to the Canadian branch of Millennium Coatings in Manitoba.

I soda blasted the rockers to clean off the years of oil crud the ultrasonic cleaner could not budge



Some wear on the pressure surface but I think they are still serviceable

One of the lifters has lost its hard surface and the rocker pins are scored but the ridge is where the spring rides on the pin so again I think they are ok to reuse

[jksymz75]

Loving this!

[canuck750]

Continuing with the disassembly, the S3 switches are shared with the T and the Le Mans MK I, fragile and complicated little buggers. Guzzi chose to feed the wires through the clip on handle bars then cover them in a plastic sheath and fit a multi pin plug on the end. Each ping has to be pulled out of the plastic holder by squeezing the tang on the pin to release it.







This bike was manufactured for the European market and unlike the V7 Sport and other American market bikes the tag on the frame does not match the number on the block





The European bike frame is also stamped to match the metal tag riveted to the headstock

Fork tubes are pitted and rusting



New ones are fairly reasonably priced and FAC dampers and progressive springs will be fitted.

Centre stand has a leg broken off



A new one will be fitted

All the parts needing re-plating have been gathered up and will sent off for new chrome.

[Cam3512]

Like I've said before.  Put you and Charlie under one roof, and you'd put Cycle Garden to shame!

Great stuff!

[canuck750]

Thanks Cam but I don't know any hot gals willing to pose in birthday suits for me,... and Mrs. Canuck would definitely kaibosh any such form of cycle promotion. The only pair of jugs in my shop are aluminum castings. ;D

[Antietam Classic Cycle]

Like I've said before.  Put you and Charlie under one roof, and you'd put Cycle Garden to shame!

Great stuff!

Jim has that covered by himself!  ;)

[canuck750]

I spoke with Fast Industries (the Canadian branch of Millennium) in Manitoba, after a short discussion I mailed off the original cylinders and two NOS pistons, they will plate the bores and size them to the pistons. I also sent them the heads, new guides, valves and springs plus the retainers, spring shims and caps, they will grind the valve seats and shim the valve springs, and I asked them to deck the heads while they are in there.

So back to the garage, the swing arm pins came out easily, thank goodness



And the various side stand parts



Out comes the swing arm and rear drive



The U joint is toast, one bearing cap has collapsed and the rollers are sitting above the carrier bearing with lots of detritus, the U joint wiggles back and forth a good 1/4", yikes!



Carrier bearing was really in tight, removed the circlip and broke out the trusty slide hammer blind bearing puller and a lot of violence



Carrier bearing is good, thought the shot U joint would have given it some grief

Then the pivot bearing seats



The tapered pivot bearings are notched, into the bin they go

Back to the frame, motor fitted the engine stand on the hoist, hang the frame from the overhead rail and then drop the lower frame rails and lower the hoist and down comes the engine and transmission





Off come the fork tubes then the upper triple, the head stock nut was finger tight



Bearing stuck, a block of aluminum and a whack of a big hammer and the stem and lower clamp are free



Bearings are notched, more parts for the bin

This handy tool is for driving out head stock races, works great every time, slip it into the frame, push the tangs down onto the race and whack the top of the tool, out comes the race with no damage



Just a few more big assemblies to strip, wheels, engine and transmission



Then I just have to clean, replace, paint, plate, polish and put it back together, easy

[balvenie]

Love the pics ;-T
Crikey you've got some tools ;D

[canuck750]

I admit it, I am a tool addict

I think I buy 'projects' to justify buying more tools ::)

Cheers

Jim

[nick949]

There's a nice article on an S3 by Nolan Woodbury in the most recent issue of RealClassic magazine.  ;-T

Nick

Here's the link to subscribe - it' rarely available on the shelves.
http://www.classicmagazines.co.uk/subscription/rc/real-classic