Author Topic: Transmission judder  (Read 5230 times)

Haarek

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Transmission judder
« on: May 31, 2014, 09:46:53 PM »
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

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Re: Transmission judder
« Reply #1 on: May 31, 2014, 10:01:34 PM »
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.
"They have nothing in their whole imperial arsenal that can break the spirit of one Irishman who doesn't want to be broken."   Bobby Sands...

Haarek

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Re: Transmission judder
« Reply #2 on: May 31, 2014, 10:14:37 PM »
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

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Re: Transmission judder
« Reply #3 on: May 31, 2014, 10:18:00 PM »
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.
"They have nothing in their whole imperial arsenal that can break the spirit of one Irishman who doesn't want to be broken."   Bobby Sands...

donandrews

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Re: Transmission judder
« Reply #4 on: May 31, 2014, 10:38:59 PM »
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
2012 Like 200i   
Lusting for People 300GTI, but recently purchased Vespa 250GTSie instead.
Brownsville OR 
Home of Willamette Country Music Festival and
movie "Stand By Me"


Normal is Relative

zombie

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Re: Transmission judder
« Reply #5 on: June 01, 2014, 01:09:39 AM »
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.
"They have nothing in their whole imperial arsenal that can break the spirit of one Irishman who doesn't want to be broken."   Bobby Sands...

donandrews

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Re: Transmission judder
« Reply #6 on: June 01, 2014, 04:15:50 AM »
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
2012 Like 200i   
Lusting for People 300GTI, but recently purchased Vespa 250GTSie instead.
Brownsville OR 
Home of Willamette Country Music Festival and
movie "Stand By Me"


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Wil B.

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Re: Transmission judder
« Reply #7 on: June 01, 2014, 12:21:19 PM »
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 

Wil B.

2010 Kymco Yager 200
2004 Ktmco Super 9
2014 Honda CTX
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kneeslider

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Re: Transmission judder
« Reply #8 on: June 01, 2014, 03:11:35 PM »
If you ever have the chance to test ride a SYM Max 400, that thing shudders like a wet dog.
2019 Yamaha X-Max 250

Stig / Major Tom

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Re: Transmission judder
« Reply #9 on: June 01, 2014, 05:59:19 PM »
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?)
Boston Strong
Rural Ohio

And, I'm feeling a little peculiar.

Stig / Major Tom

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Re: Transmission judder
« Reply #10 on: June 01, 2014, 06:31:42 PM »
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?
Boston Strong
Rural Ohio

And, I'm feeling a little peculiar.

kneeslider

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Re: Transmission judder
« Reply #11 on: June 02, 2014, 12:28:53 AM »
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.
2019 Yamaha X-Max 250

zombie

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Re: Transmission judder
« Reply #12 on: June 02, 2014, 04:59:14 AM »
Love your posts Stig!

I tried brain surgery w/ spoons once. It didn't go so well.
Zombie
"They have nothing in their whole imperial arsenal that can break the spirit of one Irishman who doesn't want to be broken."   Bobby Sands...

bluesin

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Re: Transmission judder
« Reply #13 on: June 02, 2014, 08:46:36 PM »
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 .
"There is a Fifth Dimension beyond which is known to Man. It is a Dimension as vast as Space and as timeless as Infinity......It is an area which we call 'The Twilight Zone' .   "Rod Serling

zombie

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Re: Transmission judder
« Reply #14 on: June 04, 2014, 03:06:33 AM »
I got confused in the mirror. Everything was backwards. :o
"They have nothing in their whole imperial arsenal that can break the spirit of one Irishman who doesn't want to be broken."   Bobby Sands...

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