Clutch Slipping with New Springs...Update Fixed

[Tom H]

Here is the background.

I converted my Ambo 750 to a V1000 roundfin with a Loop 5 speed and rear drive. A few technical hurdles, but all went well. I used the original clutch plates that were doing fine in the 750 but I didn't use the "original" factory stock strength springs. I bought the MG Cycle medium kit instead of using the old 750 springs. The clutch plates looked good and not oil soaked.

I put it all together, everything went well until.... the clutch started slipping when I was rolling along and hit the gas. The clutch feels great, grips fine when starting up and has the correct free play everywhere that it should. Handlebar lever has plenty of play and the trans lever has plenty of play. Nothing hitting or binding anywhere.

Now the questions.

Has anyone tried the medium spring set? Results?

Is the V1000 that much stronger that it could slip the plates when the 750 couldn't?

Did the V1000 use the heavy springs? (I have the heavy ones in my Eldo, they are heavy compares to the original Eldo factory springs.)

If so, is the 1000 why they made the heavy springs?

I really don't want to have to tear it down a bunch more times experimenting with the old 750 springs or buying new stock heavies like my Eldo has and finding it still slips. Maybe the discs have some oil on them that I did not notice and they were fine in the 750?

I thought about buying the SD Tech kit and the medium springs. Right now I kinda feel like I would be in the same place and questioning the springs.

What do you think?

Edit: If the consensus is the old clutch is not up to the job, I'll buy the kit, but what about the springs.

Thank you,
Tom

[Antietam Classic Cycle]

Here is the background.

I converted my Ambo 750 to a V1000 roundfin with a Loop 5 speed and rear drive. A few technical hurdles, but all went well. I used the original clutch plates that were doing fine in the 750 but I didn't use the "original" factory stock strength springs. I bought the MG Cycle medium kit instead of using the old 750 springs. The clutch plates looked good and not oil soaked.

I put it all together, everything went well until.... the clutch started slipping when I was rolling along and hit the gas. The clutch feels great, grips fine when starting up and has the correct free play everywhere that it should. Handlebar lever has plenty of play and the trans lever has plenty of play. Nothing hitting or binding anywhere.

Now the questions.

Has anyone tried the medium spring set? Results? No, I was waiting for someone else to be the "guinea pig".

Is the V1000 that much stronger that it could slip the plates when the 750 couldn't? No

Did the V1000 use the heavy springs? (I have the heavy ones in my Eldo, they are heavy compares to the original Eldo factory springs.) Not that I'm aware of.

If so, is the 1000 why they made the heavy springs?

I really don't want to have to tear it down a bunch more times experimenting with the old 750 springs or buying new stock heavies like my Eldo has and finding it still slips. Maybe the discs have some oil on them that I did not notice and they were fine in the 750? How thick were they? If any oil contamination, that could be the issue.

I thought about buying the SD Tech kit and the medium springs. Right now I kinda feel like I would be in the same place and questioning the springs.

What do you think?

Edit: If the consensus is the old clutch is not up to the job, I'll buy the kit, but what about the springs.

Thank you,
Tom

[jwinwi]

I'd try new friction plates. Been my experience that the last $100 invested in a project is the most important. YMMV...

[Tom H]

Charlie. Just to be clear. If I would have used the plates and the springs that were fine in my 750 and put them in the 1000, it "should" be working the same in the 1000?

If this is the case, I'll swap the springs and see what happens.

Thanks so far!
Tom

[Tom H]

After about 4 hours and changing out the springs to the stock old 750 Loop ones. Still no love.

Plates look fine, held up to the 750. Not so for the 1000.

My Eldo has a heavy set that I bought many, many years ago. Maybe these are the springs I need to use??? BTW: the set I pulled from he 750 had red paint on them. I don't remember the color on the heavy set in the Eldo.

I'm tempted to try a set of heavy springs, but I'm kinda getting over tearing it down for clutch issues. Heck, I haven't had a chance yet to see if the fuel and ignition are good. I start up and all is fine, I grab second and seems fine until I give it some gas and the revs go up and then work their way down to actually picking up speed, then grab third and give it some gas and the revs go up and work their way down again. If I hold the throttle while it's slipping, it will finally get a bite and start going. The way it does it does not feel like a oiled clutch. When I had an oiled clutch, it just kept slipping, never hooked up.

Thanks again!
Tom

[moto-uno]

  This sounds very similar to a bike I built from bits . The bike had a 5 speed from possibly ebay ( it was 10 years ago)
and upon assembly something felt wrong , like there was pushback when the trans case was around a mm or so from
bottoming on the engine case . Turns out the transmission output shaft was actually pushing against the clutch pressure
plate . This was discovered after putting it together and blaming it on something else . The roadtest had noticeable clutch
slip . Tear down showed the clutch to be okay , so I simply ground the end of the mainshaft with a hand grinder and the next
ride showed almost no clutch slipping . The bike was stripped for parts for another project before I got around to grinding
more off the transmission shaft . I'd never heard of this before , and maybe it was unique , but it's worth carefully checking.
A long straight edge and caliper are the only tools you need to see if this might be a problem .  Peter

[Tom H]

Moto, you could be on to something there.

Background: I had this trans and clutch set coupled to my Ambo 750 and did not have any clutch problems.

I know the Tonti flywheel looks a bit different from a Loop flywheel. Could the T flywheel have more of a difference than meets the eye, like need to measure and compare the thickness where it bolts to the crank????

What's a few more hours to see if the input hub is pushing against the pressure plate.

Thanks again,
Tom

[Rolf Halvorsen]

Did you put in the friction plates the right way?

The friction plates shall be assembled with the highest center part facing against the rear wheel.

This can be the reason why your clutch is slipping.

Rolf

[moto-uno]

  Rolf's remarks are also a possibility , but if you have a straight edge and a long caliper , I'd  measure from the end of the trans input shaft
to bell housing and from the engine bell housing to plate that the clutch push rod pushes against .( I don't remember which flywheel I used .)
Measure carefully and tell us what you find .  Peter

[Tom H]

Rolf, yes the high side if facing the rear wheel.

Here are some pics. Look close at the pressure plate. I think the hub is hitting it. I don't remember it looking like this when I started, but I can't say that I looked at the center, mainly at the friction area. The springs are the medium set in this picture. As I mentioned, the 750 springs are in it now.





Again, this set of parts and the trans worked fine in my Ambo 750, no clutch problem. Rode it for a few weeks with this 5 speed and a Eldo rear end before I changed it back to a 4 speed and rear end.

Thanks again!
Tom

[Antietam Classic Cycle]

Again, this set of parts and the trans worked fine in my Ambo 750, no clutch problem. Rode it for a few weeks with this 5 speed and a Eldo rear end before I changed it back to a 4 speed and rear end.

Perhaps the 1000 engine's "bellhousing" is slightly more shallow than the 750's? That would allow the clutch hub to slide deeper into the clutch and foul the pressure plate. Just an idea. Could measure than the transmission mounting surface to the center of the crank and see if there's any difference.

I would still do everything possible to remove any trace of oil from the friction plates though.

[Tom H]

Charlie, I started with a white rag and rubbed the friction plates. Mainly clutch dust, I say mainly because one plate had a very thin ring of black nearest the splines. The rest of that plate was just dust. I cleaned that plate and then used a very find sand paper to break the glaze. Reassembled and still had it slip.

After looking at my pressure plate pic last nite, It got me really thinking about why the hub would hit the plate. Again...if it is????

Charlie has a good one, if the engine bell housing is a bit shorter on the V1000. Could the end of the crankshaft that the flywheel bolts to be longer pushing the flywheel back? Is the thickness of a 1000 flywheel thinner than a Loop at the mounting holes?

Per MG cycle, the ring gear is the same, SD Tech clutch kit, pressure plate all are the same. The only difference is the flywheel.

Thanks again,
Tom

[Tom H]

It's apart again. Here is what I found.

The pressure plate I'm 99% sure is hitting the trans input hub. The plate has a wear pattern where the hub could be rubbing.

I measured how far out the flywheel was sitting out from the engine case. The 1000 and 750 were within about .3mm. May have even been closer.

I had a ring gear with bad teeth. Took a look at it any to compare to the 750's. The are where the friction plates ride was substantially thinner on the 750's than the bad tooth one. Almost flat, where the bad one still had a raised area.

The friction plates to me look fine, plenty of material before getting to a rivet. I measured them, one was about 6.5mm the other was about 6.9mm. I grabbed the manual and it says to replace when they are worn to less than 7.5mm.

It's looking like the culprit is the worn friction plates. I'm used to car plates, you can run them down until the rivets are eating up the flywheel and pressure plate. It appears that Guzzi plates need to be replaced long before the rivets will hit.

I still find it strange that the clutch seemed fine in the 750. Maybe the power difference? Maybe I only had a few more weeks of riding it before it started acting up??? The 1000 would start up from a stop just fine and accelerate fine with light throttle, but when I gave it a twist to see how a 1000 felt, that is when it would slip.

Thanks again for the help!! At least now when I put new plates in it won't be a waste of money. I'm pretty sure they will fix the problem. I may also get a new ring gear while I'm in there.

Tom

[Chuck in Indiana]

At least now when I put new plates in it won't be a waste of money.

Well, there ya go..   

[Tom H]

New SD Tech set installed and went for a spin. No slipping, all good now!!!!!

Thanks for the help!!
Tom

[jwinwi]

I'd try new friction plates. Been my experience that the last $100 invested in a project is the most important. YMMV...

You're welcome.

[Tom H]

I forgot to mention that I went with the stock red paint springs from my 750. In my 750, the clutch lever was easy to pull, with new plates it's about as stiff as my 850. I guess the springs felt easy to work because the plates were so worn. I should have tried the medium spring set. I will the next time I need to get in there.

Tom

[moto-uno]

  I'm imagining that will be long into the future  .  Peter

[Mike Harper]

Quote from back in the 60s.  "Chrome won't get you home"

[Mike Harper]

Quote from back in the 60s.  "Chrome won't get you home"

Chrome clutch Springs??  In a Guzzi?  Why?  Do you know what they really fit?

Can not be seen from the outside when assembled so it is a real stretch to think they are really for a Guzzi to begin with. Gotta be from some open clutch assembly like a HD or Indian or some other make or  model that we don't see in the USA.

[Curtis Harper]

Clutch springs in all big twins were the same part / part number from 1966 thru the 2012 Cal vin. Also same spring was used in lemans, Daytona and even MGS01. Under a quick look the only thing that used a different spring were the 10 spring clutches. Most all of those bikes make substantially more power than the G5. If they don't slip in the MGS01, they should not be the problem in yours. I see what looks like a warped center steel plate in one of your pictures which would definitely be a major cause of clutch slipping. I would question the logic behind a "Medium" weight spring which also would not put and mush pressure on the friction discs and of course cause slipping.

[Cam3512]

Glad you figured it out.  I could not understand why you went through all that work and installed used friction plates.

[Tom H]

Cam, because they worked fine in my Ambo 750. I thought they were still just fine for many more miles.

Curtis, they may not be chrome, they may be shinny silver, click on the pic I posted of them. The silver ones, using the highly accurate finger squish test, feel like the old red paint ones. The black one are much softer.

On the spring strength. Yes, the what I call red paint springs were used on just about everything from what I understand. Somewhere in the mid to late '80's I bought a set of springs from B.J. when he was in Hesperia. He said that it was a heavy set, stronger than stock. They felt heavier than what was in it, and he said my springs were usable but since I was in there......

Again, thanks for all the help,
Tom