JGP

Capisce.

Don't follow. Are you suggesting the Schnorr type washer is not a lock washer and a split ring washer is?

Off topic. I have a rear tail light for an Aermacchi. Coffee can style. I bought it about 20 years ago on a whim. If you know anyone that may be interested in it, let me know. I need to go look for it, I think it was pretty much NOS.

I do.

There is, on the single-plate clutch's aluminium flywheel, a steel "donut" that mates to the flywheel under the 6 bolts. I expect, that is intended to spread the force of the bolts over the flywheel surface (30 ft/lbs). I don't know how the dual-plate is set-up. I would not expect that there is any further need for a washer on those bolts, other than a possibly a lock- washer, depending on how you feel about it. All I know is that the factory use of washers and "Loctite" is inconsistent to the parts book or the repair manual as my ring gear bolts had no washers (locking or otherwise) but did have the "special sauce" applied. Additionally, there is no gap between the inner edge of the ring gear and the outer edge of the bolt. So, any washer used would need to have the same width as the head of the bolt. The transmission mounting studs had a combination of lock-washers and washers on some studs, and no washers on others, only lock-washers. Diagram A1 of the parts book identifies one stud has having a washer (4X) and the other that has a coupling bushing as not having a washer. There are 6 studs. So, i expect what the parts book is indicating is that where there is a coupling bush, do not use a washer, as 2 studs have coupling bushes. I had only 2 washers on all the studs, every stud had a lock washer.

Thanks for your thoughts. The ring gear bolts, for example are only torqued to 12 foot/lbs. Not high torque, so I don't believe there is a lot of stress that needs to be spread. To your point, nearly 25 years and they were solid when they came out.

I am not sure if anyone has noticed the same, or has any thoughts on this, but there are 12 bolts in the single plate clutch. 6 bolts for the flywheel, 6 bolts for the ring gear. The parts book shows all those bolts with lock washers. In my parts book, the single plate clutch is not broken out in detail and it reflects only the dual plate version. In any event, there were no lock washers on any of those bolts. I am thinking that because they were put on with MG's "special sauce" they did not bother to put lock washers on. I am going to order washers, but I am curious if others have noticed the same. Alternatively, it may have been built on a Monday, a Friday, or the day after Grappa Day....

Yeh, does not stand the test of time. BTW your electronic cleaner trick works like a charm. Good find.

Noted. Thanks for the info. No rust, just clutch dust and a little oil, probably from either the bottom of the breather hose/tube or the Welch plug (or whatever term preferred) for the cam. Clutch dust and oil makes for a pretty strong bond. I am going to paint the seam on the plug with 3 coats of Glyptal Red. Put some vw silicone sealant (they make a pretty good product $$$) on the breather tube gasket and look for a better clamp to the breather hose. Follow some of the other points in Docc's thread. I don't see the point in changing seals at 10K miles, even if it's getting up in years, they all look good. I put sealant on the 2 lower bolts on the crank flange. They were dry and had been factory-treated with some sort of sealant that was a mix between glue and bubblegum.

It's the standard, Scura/Tenni clutch, some sort of bronze composite. I wrote 10K miles = 1/2 life. Which is in-line with what other Scura owners have reported-changing out clutch plate at around 20K miles. On mine, wear is primarily due to wear on friction material, the splines are showing a little wear, but nothing that I am worried about failing before the clutch material wears out.

I had a stop watch on you Pete! Your views on Surflex are well understood. I have 10K miles on my single plate Surflex and it has 1/2 life left, and I like to rip with the best of them. That is not uncommon wear from what I have read others report. That's why we have Ford v. Ferrari; It makes the world go 'round. I have no financial interest in Surflex. I am not sure that all the swap-out proponents can say the same about the products they are standing behind....just sayin'

Not sure? In case anyone is interested, I could be well into the minority on this one, Surflex is going to restart production of the original clutch plate for the single plate V11 clutch. Moto Guzzi part number GU 01081940. Contrary to what I had read else where, this is Surflex part number 83 M 1. Production is to begin week 29, 2025. The notched version of that plate, Surflex 83 M 4, will be produced in 2026, no specific date given. Price is 120 euro plus shipping and handling. They are currently taking orders. They returned my email on a Saturday so, I am almost positive it's a scam. If anyone is interested go to the Surflex website and send an email to their contact email address requesting information. English language is fine. If this needs to be moved elsewhere, please feel free.

Thank you! I think I can add oil pan gasket to my list as well.

Yup. After nearly 25 years, and multiple repairs, i know a lot of these guys. I used to use Joe Eish a lot, he was out in Ohio, a long time ago. I have seen people put some sort of sealant on the Welch plug. I think that was part of the problem. Any recommendations on what sort of sealant?

BTW if anyone has original Scura/Tenni clutch pressure plate or clutch disc, in good shape, hanging around from their single plate swap, I am a buyer. Please contact me.

Drama is over. I was going to perform the bench test above, I was cleaning up the parts, when it hit me that something was not right. One side of the clutch plate was "welded" to the clutch disc that bolts up to the ring gear side of the clutch. Not sure how I missed that, but that's all part of the DIY life. It welded due to the clutch dust and other moisture (s) in that general area. I am on the hunt for a thread where Docc outlined certain seals and plugs that are readily accessible with the engine and transmission out. If anyone knows off the top where that is, I would appreciate a link. Thanks to all for their help.

IDK either. I think I am going to try to assemble the clutch pack outside the bike and put pressure on the inner thrust body until I have about 1/8" travel and see if it frees up the clutch plate. If it does not, then I can only assume it's the pressure plate.

I have already replaced the slave with a new one from Denmark. No change. So to recap. Rebuilt the master, no change. Installed a new slave, no change. Rigged the slave with washers, no change. Pulled the engine and the tranny and no visible damage. Not sure where to go from here. It could be that the pressure plate is out of spec. but I have no way to check that. I could buy a new clutch, but I have an aversion to being a parts cannon, until I figure out what is wrong.

I am waaay ahead of you. It was the first step in this odyssey. If it's not working with the washers in the slave, I don't think it's hydraulics related. But always ready with an open mind.

Do you mean when the clutch was working properly? If so, to the best I can recall, there was always a fair bit of free movement. It just started acting like a cable clutch going out of adjustment until there was no activation of the clutch. Most noticeable when you tried to come to a stop while in gear and the bike would keep chugging forward.

1/8" is not very much, and when I look at the pressure plate, I am not 100% convinced that 1/8" on the pressure plate will do much, but everything seems to point to this being the correct length of travel. If anyone has better info, I would be interested to know.

Maybe I was a little hasty. It's little tricky to get the outer thrust body set properly. Once it is, it will move in and out about a big 1/8th of an inch. When it goes in to the maximum, meaning flush with the inner transmission face, there is a bit of a "pop". If you move it back with the pushrod it travels with a little resistance about 1/8 or so. This is what I was noticing when I was actuating the clutch lever, the plunger in the slave would travel about 1/8". To answer your question, as I stated previously, I stacked a couple of big washers inside the old slave and reinstalled the plunger. So the plunger was fixed about 3/16" proud of the slave face. I reinstalled this arrangement with the screws which is essentially a bypass of the hydraulic system. After bolting in place, I still could not turn the drive shaft. So, I had ruled out hydraulics.

Look at you! The rod by itself moves freely. When you put the outer thrust body and the related washers, it wants to bind, if I move it around, it moves, not great, and it seems to want to lock up rather than continue to move free.

Well, it's the worst possible outcome. I can't see anything wrong. Nothing. There is clutch material dust, a tiny bit of oil that seems to be weeping from a seal in behind the breather tube and that's about it. There seems to be plenty of material on the clutch disk, both sides of the metal plate seem to have about the same amount of material 3/32 maybe an 1/8. My problem was not slippage, the opposite. I need to think about this. For what it is worth, the aluminium flywheel looks fine. I still need to clean one side but I don't see any points of concern. I am the original owner. It has 10,000 miles, totally stock. Very little city traffic, virtually zero. I don't baby it, but I don't drive it like I stole it either. That's not meant to imply that those who have had problems with the flywheel beat their bikes, just information intended as a point of reference.

Thanks. I could not think of a good reason to take it off, so I won't. I have a holding tool too, it's a broken bit of plywood with a nice taper to it. Wedges in nicely against the ring gear and a stud. Not recommended, but if you want to get it done it works. Ease the bolts out, don't crank like a gorilla or you may be looking up the part number for a new stud.