Author Topic: Scooter suddenly started shaking on acceleration and rolls forward at idle  (Read 5359 times)

mousejunks

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Downtown 350 with 30,000km.

Riding on the street in heavy traffic. Moved off from stationary and the bike started shaking/stumbling on acceleration to 40km/h. Idle speed dropped to 1400 rpm. Above 40km/h, no issues with acceleration or vibration as if it was normal.

The other issue that suddenly appeared was the bike would move forward on idle. Pulled over and noticed that the rear wheel would spin fast and could only be stopped by holding the brake.

I strongly suspect that one of the clutch pad springs broke and the pad is now engaging with the clutch bell, causing the transmission to be engaged with the rear wheel all the time.
'09 Kymco Espresso 150i
'11 Kymco Downtown 300i ABS - 79,500km
'17 Kymco Downtown 350i ABS

Ruffus

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Re: Scooter suddenly started shaking on acceleration and rolls forward at idle
« Reply #1 on: September 30, 2023, 02:05:45 PM »
Mouse yes, I think you're on the right track.
Take off CVT housing and have a look at your clutch.

 NOT very likely but possible, a part of your belt got seperated and stucks somewhere.
All symptoms hint towards this clutch.
Happy and safe scootering, Ruffus

Iahawk

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Re: Scooter suddenly started shaking on acceleration and rolls forward at idle
« Reply #2 on: September 30, 2023, 02:24:22 PM »
yes, I think you both nailed it...a rear wheel always moving means the clutch is somehow always engaged. Tear it apart and see what you find! (and then be sure to let us know!)
2010 People S200 - sold after 8 wonderful years!
2014 Ninja 300
1996 Honda Helix
1984 Honda Nighthawk 650

Ruffus

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Re: Scooter suddenly started shaking on acceleration and rolls forward at idle
« Reply #3 on: September 30, 2023, 09:10:37 PM »
But Mouse, couldn't this scoot simply be afraid and started shakin'?😉
Happy and safe scootering, Ruffus

mousejunks

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But Mouse, couldn't this scoot simply be afraid and started shakin'?😉

Yes it was afraid to go to work.  ;)
'09 Kymco Espresso 150i
'11 Kymco Downtown 300i ABS - 79,500km
'17 Kymco Downtown 350i ABS

mousejunks

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Just an update - this is what is looked and sounded like before taking it to the mechanic. Why mechanic? It would be the first trip in the scooter's lifetime and it'll be good to know what they want they plan to do with it.

'09 Kymco Espresso 150i
'11 Kymco Downtown 300i ABS - 79,500km
'17 Kymco Downtown 350i ABS

Ruffus

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Mouse, sounds like belt and/or clutch to me. Maybe front pulley/rollers too...
Would be interesting what they find on there.

.
« Last Edit: October 02, 2023, 08:59:08 PM by Ruffus »
Happy and safe scootering, Ruffus

Ericson

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I had similar issue when I put chinese 15g 20x12 sliders. Clutch was engaging on idle rpm's. When I swapped sliders for 15 g 20x12 rollers problem was gone   :o
« Last Edit: October 02, 2023, 09:56:17 PM by Ericson »

Ruffus

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Interesting what Ericson says.

Had the same issue with original TechPülley "gliders", after I polished the CVTs ramps and the pressure plate it ran normal again
Happy and safe scootering, Ruffus

Stig / Major Tom

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My $ on flipped Dr P's....(which aren't in there)...so more $ on the clutch.  Spring broke or pad came loose?
Easy to spot and fix once belt cover removed.

Stig
Boston Strong
Rural Ohio

And, I'm feeling a little peculiar.

mousejunks

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Re: Scooter suddenly started shaking on acceleration and rolls forward at idle
« Reply #10 on: October 03, 2023, 02:10:03 AM »
I had similar issue when I put chinese 15g 20x12 sliders. Clutch was engaging on idle rpm's. When I swapped sliders for 15 g 20x12 rollers problem was gone   :o

All stock rollers for me because they work. Never used sliders for this bike.
'09 Kymco Espresso 150i
'11 Kymco Downtown 300i ABS - 79,500km
'17 Kymco Downtown 350i ABS

mousejunks

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Re: Scooter suddenly started shaking on acceleration and rolls forward at idle
« Reply #11 on: October 04, 2023, 07:18:40 AM »
Update:

Mechanic says a roller shattered and caused lots of damage to the CVT. According to them, looks like most of the CVT parts will have to be replaced, including the belt, clutch and pulleys as they are all damaged. I'm very shocked this has happened.

I'm thinking if this is done it will be $$$, but I won't have to do any major CVT maintenance for a long time - at least for the next 20,000km. I normally do maintenance myself this is not maintenance but a significant repair job.

Thoughts?
'09 Kymco Espresso 150i
'11 Kymco Downtown 300i ABS - 79,500km
'17 Kymco Downtown 350i ABS

Stig / Major Tom

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Re: Scooter suddenly started shaking on acceleration and rolls forward at idle
« Reply #12 on: October 04, 2023, 09:38:05 AM »
Not sure what the replacement interval for roller weights is on your scooter. At 30,000km, were they ever replaced or at least inspected?
That said,  never heard of a CVT weight shattering!
Stig
Boston Strong
Rural Ohio

And, I'm feeling a little peculiar.

mousejunks

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Re: Scooter suddenly started shaking on acceleration and rolls forward at idle
« Reply #13 on: October 04, 2023, 09:51:35 AM »
Not sure what the replacement interval for roller weights is on your scooter. At 30,000km, were they ever replaced or at least inspected?
That said,  never heard of a CVT weight shattering!
Stig

A roller shattering is shocking news and unheard of. Will have to go to the mechanic to confirm.

Yes they were replaced at 20,000km, along with the drive belt. There is no interval in the manual, only inspection and replace if necessary, which they were.
'09 Kymco Espresso 150i
'11 Kymco Downtown 300i ABS - 79,500km
'17 Kymco Downtown 350i ABS

Ruffus

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Re: Scooter suddenly started shaking on acceleration and rolls forward at idle
« Reply #14 on: October 04, 2023, 11:41:15 AM »
Sorry to read that, Mouse!
Since a CVT consists of a lot of parts, I would not take the mechanics statement as granted.

Front pulleys? What happened to them? Clutch, completely disintegrated? Belt, okay, should be.
Demand documentation of all this .

All complete CVT inclusive clutch and belt should not be more than €500,- for your scoot, plus two hours of labour.
 Do they charge you for diagnostics too?
« Last Edit: October 04, 2023, 11:43:27 AM by Ruffus »
Happy and safe scootering, Ruffus

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