Transmission judder

[Haarek]

From the scooter was new the transmission judders on take-off. Nothing dramatic, but it feels like the clutch slips a tiny bit before catching and then slipping a bit again. From around 10-15km/h the judder disappears and the scooter accelerates smoothly. The problem lessens after warming up. At first I thought the clutch only needed to get run-in, but I am approaching 4000 km and it is still there. Other than the juddering at take-off I don't think there is any undue slippage in the clutch during normal driving. Any tips or is this in the category "feature - not a bug"? Can the clutch shoes be glazed?

[zombie]

Every scooter with a cvt has the same issue. You have to modify the way you take off to by-pass the rpm range where this occurs. Not saying you have to burn out or pull wheelies but just get a bit tougher w/ the throttle just before the shudder happens, and let back off if needed after that range has passed.

You can also buy better clutches but the issue will remain. It is really the nature of the beast so to speak.

 The pads, and bell can be deglazed every few thousand miles by taking the bell off, and scratching up both surfaces w/ a Scotch Brite or Emory Paper.

Some will recommend power braking the bike to burn off the glaze but in the long run it is NOT a good idea to super heat these parts.

[Haarek]

Thanks for the reply. "Feature" then 

Can't say I remember having this problem on my previous scooters, but they where 50cc, so there might not have been enough power to really make anything shudder on those.

[zombie]

Actually I can make the 50's do the same thing if I try to take off slowly. Like you said it's a power thing. 50cc's are usually on or off on the throttle, and you sort of power right past the "poor" spot.

[donandrews]

Haarek - thanks for bringing this up and Zombie - thanks for the answer. I noticed my Like 200i starting to shudder after about 4,000 miles. May have done it sooner, but that's when I started noticing it. Happens only on starting off and quits at about 10 mph. Goes away when I get on the throttle a bit more. Mentioned it to my mechanic. He said was probably the clutch and not to worry about it unless got worse. Was a common thing with scooters. And Zombie, what you say is correct. A little more throttle and it doesn't happen. But I'm still going to have the mechanic look at it when I go in for 6,000 mile oil change soon. This is way beyond my wrenching skills which stop with checking the oil every once in a while.
Peace and Ride Safe,
Don

[zombie]

It's a good idea to deglaze the clutch around oil change time. It creates a reason to inspect the rest of the cvt parts as well.
 Worn rollers / drive bosses / ramp plate guide bushings will often give the same shudder but that is usually accompanied by rattling noises, and/or a defined "clunk" on acceleration/de acceleration.

[donandrews]

It's a good idea to deglaze the clutch around oil change time. It creates a reason to inspect the rest of the cvt parts as well.
 Worn rollers / drive bosses / ramp plate guide bushings will often give the same shudder but that is usually accompanied by rattling noises, and/or a defined "clunk" on acceleration/de acceleration.

Zombie -Thanks for the tip(s). No rattles or clunks yet other than my old bones going over rough roads. Wish the Like had a little better suspension.
Peace and Ride Safe,
Don

[Wil B.]

My mechanic (Honda-Kymco dealer) said that this shudder is pretty common on larger displacement scoots including the Hondas.  They cleaned out the transmission (no charge).  The fix lasted a week or so on my Yager 200gt and comes and goes.  The shudder happens at the same mph as the other posters here.  I've learned to give it MORE THROTTLE to get through this rpm range smoothly.  I'm not going to go into the transmission every month just to clean it! This is the only fault I can find with my Yager which has been a wonderful ride.

My 50cc scoots never have this problem.  So I fear this is just endemic to larger displacement scoots.

Wil B.
Broadview, IL

'71 Guzzi Ambassador
'91 Honda Nighthawk 750
'04 Kymco Super 9
'10 Kymco Yager 200gt 

[kneeslider]

If you ever have the chance to test ride a SYM Max 400, that thing shudders like a wet dog.

[Stig / Major Tom]

If you ever have the chance to test ride a SYM Max 400, that thing shudders like a wet dog.

Or, like a greyhound passing a brick.
(but, surely that was a one-off malfunctioning scoot?)

[Stig / Major Tom]

Haarek - thanks for bringing this up and Zombie - thanks for the answer. I noticed my Like 200i starting to shudder after about 4,000 miles. May have done it sooner, but that's when I started noticing it. Happens only on starting off and quits at about 10 mph. Goes away when I get on the throttle a bit more. Mentioned it to my mechanic. He said was probably the clutch and not to worry about it unless got worse. Was a common thing with scooters. And Zombie, what you say is correct. A little more throttle and it doesn't happen. But I'm still going to have the mechanic look at it when I go in for 6,000 mile oil change soon. This is way beyond my wrenching skills which stop with checking the oil every once in a while.
Peace and Ride Safe,
Don

Dear oil checking Don,
OK, after he opens that belt cover (will 6000 be the first time it's off?) - you will be like a naked man in the warm ocean! "Free of worries & giggling a bit" - & happy knowing that thing will practically fall off the next time you remove those 8 bolts. (the belt cover we're talking about here! )
Getting that dumb cover off the first time is ...hard. But after that, it is time to get yourself a couple of tools and go back in there yourself....to take off the belt, and clutch, and variator and rollers, etc. and hold them in your hand and roll them around on the kitchen table & have a coffee and marvel at the engineering of scooter guts ...and at your newfound mechanical prowess! You'll feel (nervous, a bit - because now you gotta get them all back in there again without screwing up your perfectly fine running scooter) great that you've bonded with your pretty scooter and the Family Innocenti !
Perhaps other than getting that front leg shield off or removing a tire from the rim with soup spoons you have accomplished the equivalent difficulty of brain surgery on your scoot. You can now play golf on Weds afternoons at The Club with the Guys From India who fix our hearts. Next up are the valves!

I am no Giuseppe Piaggio.....but I am living proof that mechanics of big hands and small minds can do a roller change on these things. Sure Orientals are a LOT more clever than us Gringos, but we can & do catch up when they stop for soup.
You can do this thing Mr.DonAndrews !
Stig
what was the question again...
and who moved my cheese?

[kneeslider]

Or, like a greyhound passing a brick.
(but, surely that was a one-off malfunctioning scoot?)

Nope, all SYM MAX400's does that, the shuddering at low speeds when the CVT is taking up the load.

[zombie]

Love your posts Stig!

I tried brain surgery w/ spoons once. It didn't go so well.
Zombie

[bluesin]

Love your posts Stig!

I tried brain surgery w/ spoons once. It didn't go so well.
Zombie

Spoons work great when I do Neurosurgery.... scoop out the bad part/all better .

[zombie]

I got confused in the mirror. Everything was backwards.