Modern Vespa

I think I've got it.

At low RPM's as I move slowly from a standstill to speed, I get that grunching sound/shudder for a moment or two until everything gets itself together. My belt and rollers are relatively new. I changed them just before the winter set it. If I accelerate quickly, no sound. Nothing unusual at speed either.

So I'm assuming the problem is with the clutch pads/bell engaging smoothly.

It's more of an annoyance than anything...still...

Before I take things apart, my search results tell me to blow out the dust, check the inside of the clutch bell for any unusual wear, and abrade it a bit with green scotchbrite pads. Anything else? Should I do anything to the clutch pads?

I've also come across some people saying if the bell is out of round, that could cause a similar problem. How common is that?

Thanks.

scotch bright will do nothing but make it shine

200 grit sand paper, then blow out the dust. make sure it's scored up something good.

I get shudder every once in a while and just blow out the clutch bell with Brakleen. (Thanks to fellow MVers for teaching me that trick). You dont need to even take the engine housing off and it works fine in cleaning grime off your clutch that causes shudder. Just take off the Vespa cap from the engine cover and stick the straw inside and blast away. Have some paper underneath to catch the mess.
Works for me..Unless you have a more serious issue, then this might not work for you...but couldnt hurt to try.

Brakleen?
Is that the CRC 'brakleen'
sounds very easy


Coggo

+1 on the Brakleen for the clutch.

Brakleen also cleans dirty rifle receivers and kills hornets on contact. Useful stuff.[/u]

Brakleen is great stuff, and I do advise trying that first, but it won't solve any problem if the drum is glazed. It helps if the shoes are slipping on dust but not if the contact surface isn't prime for mating.

Ooo this is post 4000. Yikes.

Humidity is enough to make rubber on steel a bit grabby...particularly if you've got some morning dew.

i had the same experience as menhir .. thought it was my belt going or something. Humidity is high all year round where i live, coupled with the fact that it has been raining almost daily ..

As usual, MV comes to the rescue to help me understand my scoot better ... thanks ALL

Take the clutch assembly outside and use a compressor and blow the crap out of it. If yours is like mine the dust cloud will really surprise you. Make sure your standing upwind Then put (1) Drop of oil on the pivot points and reassemble.

Sandpaper the inside of the bell housing but dont get carried away

So there are no bearings, etc. to be damaged by the Brakleen and the belt is impervious too? (I've never taken the full cover off, just the little chrome cap.) Brakleen dissolves almost anything, that is why I ask.

I appreciate all the help.

When I replaced the belt and rollers late last year, I remember thinking the bell was very smooth inside. The shudder was happening even before that point...it was just getting a little more noticeable lately. So I'm guessing it's likely the bell is glazed and I should be prepared to rough it out a bit.

I've been in the habit of blowing out the dust from time to time so I think there is more involved here than dust alone.

I picked up the Brakleen today. I never heard of that stuff before. It sounds like it will come in handy. I'm curious, too. Just spray it in the holes and be done with it, nothing to worry about, right?

did you just do it?

Coggo

Interestingly I had serious clutch shudder probs when I first bought my GT in 04. I was opening the CVT every 4000km to clean and abraid the clutch bell. Then I switched to Brakleen and over the last 18 months I have had less and less cause to use it. Sort of like the Brakleen has helped the clutch bed in over time. That and the fact thast the GT has now clocked 28000kms.
One little word of warning - use the fine nozzle, not the general spray. I have heard that the solvent in Brakleen can strip the lubricant out of the belt idler wheel.
Good luck Menhir.

That will save me some time. I was going to just sand up the clutch bell for starts because I figured the Brakleen may have only been a stopgap measure. No. I've been traveling for a while. Just got back. Just.
I'll do it today. Promise.

OK...I did it.
Just before I left for work this afternoon I used the Brakleen.

It worked!

The shudder disappeared. I rode 57 miles before I got back home, smooth as silk all the way. I never expected such a drastic difference.

Thanks!

Menhir
So just pop the chrome cover, poke in the fine nozzle and squirt away?

JC

That pretty much sums it up. 8)

brilliant, I will give it a go, Sounds too easy
Coggo

Cool. Just don't do any more "slow starts," or the clutch pads will glaze and the shudder will come back. Starting "normally" will prevent this.

Newbie question here .. what is a "slow start" vs a "normal start" . Thanks

You give it a bit of throttle and all you get is slippage or shuddering with very little acceleration.
Normal = key, start, twist....gone!

ahhh .. i see .. thanks

Does any type of brake cleaner do the job, or does it have to be brakleen (can't find it locally). Thanks.

Thought I'd post a recent experience wrt shudder and "the fix", so to speak that didn't involve the two common remedies that most people recommend: brakleen or 10 or so miles of freeway travel to blow the dust out of the clutch bell. Here's the history.

300 miles: Shudder started happening on my GTV from 300 mile point. I called the local shop and the mechanic told me to avoid slow starts. "Start hard and then back off whenever you can to avoid glazing the clutch shoes". I also tried riding at freeway speeds for 10 miles or so and that didn't help.

600 miles: At the 600 mile service, the mechanic scuffed the clutch bell and pads up with 200 grit sandpaper and said I should be good to go. the shudder came back after about 100 miles. I talked to the mechanic and told him I'd taken his advice and was gunning it on take off.

800 miles: He scuffed it up again, and it came back again after about 100 miles. We decided to change the clutch bell since it got worse after it heated up and his feeling was that clutch bell was going out of round when it warmed up.

1000 miles: It came back and it had nothing to do with warming up. We talked about what the causes might be. He says he's worked on about 800 vespas and once people avoided the slow take off, the problem went away.

1200 miles: It came back again. I got tired of taking it back in. I recently went back in and talked to him about potential other causes: belt slipping, unevenly warn rollers, .... He was insistent that the clutch pads and bell were the only things that could cause the problem

He's since cleaned it for me several more times (under warranty).

Last time I went in was a few weeks ago. They let me borrow a GTS 250 for the day. The low-end torque difference between my GTV and the GTS was quite noticeable (and enjoyable on the GTS). When I asked about it, he told me they'd replaced the GTS variator with a J Costa.

For about $350 (parts and labor I think), they replaced my variator with the J Costa. That was almost 400 miles ago. Its been smooth as silk ever since. I'm not sure what conclusions to draw other than it appears, from this limited case, that there may be other things that cause shudder, even tho its not acknowledged by the local mechanic. I think my bike was an anomaly to him in that the shudder kept coming back.

Whatever. I'm just glad its gone.
Best
Miguel

For me - the J Costa is Magic. Now down-graded in the 'best mods' stakes for an MP3 500 after Jeff's foot-peg brackets - but a very close second!

Okay--just to be clear because this just sounds WAAAAY to easy . . .

Pop the chrome cap off, and instead of blowing compressed air in there, squirt brakleen in the same hole, then ride like hell?

Did you squirt a lot in there?

Really excited to try this--my ET has been neglected since this problem flared up.

I'm glad you asked, because I should have done another follow up on this...

Yes, It's just that easy...you don't even have to ride like hell...that's optional.

But...
Yes, the Brakleen worked, but it wasn't a permanent fix...well, not for my anyway. After a while the shudder returned.

I think the problem for me was that dust buildup wasn't the problem. My long commute involves sections where there is a lot of stop and go traffic (which probably resulted in the glazing) and other sections where I'm riding stretches at 50MPH+ (which did a good job of blowing out the dust).

When I pulled the clutch bell I never found dust buildup, but it was pretty obviously glazed.

So the Brakleen was a temporary fix at best until I deglazed the bell. I did that, and the problem still returned after a while. I don't think I was aggressive enough. I just did a better job a couple of days ago...the shudder is gone but time will tell.

The Brakleen was still worth the purchase price and it's worth a try. Besides a temporary fix (or a more permanent fix for some), I still used it to clean the clutch bell after I deglazed it.

NOTE: Brakleen emits some nasty gasses...I only apply it outdoors, and I hold it at arms length.

As an aside...I was putting up with the shudder for a long time between fixes. Recently, the back plate of the clutch came loose and is rattling like hell...I'm looking for a new clutch assembly. I'm wondering if by ignoring the shudder, it resulted in the problem with the back plate.

I'd think that's entirely likely. The repeated shuddering was probably putting a great deal of strain on the rivets and eventually loosened them up.

I was told by my local scooter repairer that the Vespas never wear their clutches out but do make that noise on take off. Apparently it gets louder the bigger engine. He also said they do it more in the warmer weather or when the clutch is hot. I don't know...

I'm just going to ignore the grind until it's full service just before it's MOT.

I had nearly the same experience as Miguel's. Back and forth to the dealer, where they said they had never seen the problem before.

At about 1000 miles they got authorization to replace the variator, belt and clutch/bell. Worked great for about 500 miles then back to the same problem.

It was after the problem returned last summer that I read about the Brakleen solution. Works great! and I posted that I might buy a case of the stuff.

Then others wrote to say there were downsides to using Brakleen too often. So last fall when I had some time I pulled the cover myself, sanded the bell thoroughly and also the glazed pads lightly. Felt good to learn more about the innards.

That worked great for about 450-500 miles then it was back to the same old, same old. So now it's every few weeks with the Brakleen. If I hit it soon when I first notice the shudder it seems like much less of a problem anymore and something I can live with.

It's always been the same with the 'strangled sealion'. It's a feature, not a bug, it always comes back.

JimC,
That's what some people on this side of the pond call "putting lipstick on a pig". Thanks for your input!

Thanks for the followup. I'm definitely going to give this a shot and see if it reduces the shutter, although I'm a little apprehensive about having a can of this in my garage.

It's probably important (as you note in your wiki entry) at this point to let anyone who plans to do this that they should read the following thread (and embedded link) before using Brakleen:

Read This Thread Before Using Brakleen!

I just used this fix myself. I'm currently riding an '09 S150 with about 5500 miles on is, 2000 of which have been with a pillion. I think it worked! I used about half of the can. Since I had never had that Vespa cover off, I was curious as to which holes to spray the Brakleen into. It was obvious once I got the cover off.

That's mostly true -- it's rare to use up the whole clutch pad. You usually end up replacing the clutch mechanism (or parts therein) before the pads are worn out. The GT200 gets this quite a bit more often than the GTS or GTV. So it's not strictly a matter of engine size.

Cheers Jess, I had just popped by the garage to ask his opinion about the noise. So all in all fair response from him. Thanks for the added details just what I want to hear.

I was also having the strangled sealion noise from my GT200. The Brakleen work for a bit, but it kept coming back. My transmission case is painted and the Brakleen started to remove some of the paint. I removed the transmission case to repaint as well as scuff up the clutch bell.

Then I discovered my real problem, there was a small oil leak from the gasket on the oil pan. Small amounts of oil were getting into the transmission housing an getting flung onto the clutch assembly.

New gasket, new paint on the cover, no more Brakleen, no more slipping / groaning.

dan

Many thanks for this tip - seems to have sorted the godawful WOINNNGGG! from my GT whenever I accelerated from a standstill, at least for now...

(UK people, I used this:
http://www.getgeared.co.uk/PROCYCLE_Brake_Cleaner_750ml
A bigger can than you get in Halfords and a quid cheaper!)

Ok, having read all the warnings I'm about to try using Brakleen. One question thou - you spray with the engine running yes?
Thanks Jack

No! That will just splatter Brakleen mixed with clutch dust all over everything inside the tranny housing, including the belt and pulleys. If you are going to go the Brakleen route, use the red straw and direct the spray all around inside the clutch area through the holes in the cover. Slowly turning the rear wheel will turn the clutch bell to enable you to better get at everything through its holes.

That's the way I'd do it... if I were going to do it. Personally, I don't like the idea of using Brakleen around bearing seals. I prefer to blow the dust out with compressed air every now and then, and take off the tranny cover for a more thorough cleaning and deglazing if it gets bad.