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Scooters - 50cc => Super 8 => Topic started by: waqr on April 18, 2017, 07:17:37 AM

Title: Kymco Super 8 50cc 4 stroke - grinding noise
Post by: waqr on April 18, 2017, 07:17:37 AM
Have had a rattling/grinding noise coming from the fan side of the engine since last week. Tore apart the fan side of the motor and found nothing that looked wrong. However, this is the sound I get when I turn the gears that are inside (see link below)

What could cause this sound? Could it be something with the starter clutch? I have noticed that the starter slips occasionally whichs means that I have to release the start button and press it again to get the starter to grip and turn the motor around.

Note, I have no play in the crankshaft either on the fan side or on the variator side so I doubt it could be the bearings. Only play I have is maybe .5mm back and forth but no play left and right.

https://youtu.be/mERiocwRmRQ

https://youtu.be/VHn84OxZsr0
Title: Re: Kymco Super 8 50cc 4 stroke - grinding noise
Post by: CROSSBOLT on April 18, 2017, 04:37:05 PM
Finding nothing on the fan side, I would look in the CVT side. You DEFINITELY have something dragging! How many miles? How long have you had this bike? Are you the first owner?

Karl
Title: Re: Kymco Super 8 50cc 4 stroke - grinding noise
Post by: waqr on April 19, 2017, 05:30:40 AM
Quote from: CROSSBOLT on April 18, 2017, 04:37:05 PM
Finding nothing on the fan side, I would look in the CVT side. You DEFINITELY have something dragging! How many miles? How long have you had this bike? Are you the first owner?

Karl

I have looked at the CVT side. Replaced the rollers and installed a new belt. Can`t understand what is causing this sound.

I have roughly 5000 miles on the bike and I am the second owner. I have had it for almost a year and just one owner before me.

Would really appreciate if someone could help me figure out the problem.
Title: Re: Kymco Super 8 50cc 4 stroke - grinding noise
Post by: waqr on April 19, 2017, 08:39:46 AM
Looked at the flywheel today and noticed 4 indents approx 90 degrees apart inside of it. Also noticed some scraping marks on the magnet. When I rotated it by hand I couldn`t see that it was hitting the pickup coil.

Should it look like this?

(http://i68.tinypic.com/289jwj7.jpg)

(http://i67.tinypic.com/r70j6q.jpg)

(http://i63.tinypic.com/10gkx04.jpg)
Title: Re: Kymco Super 8 50cc 4 stroke - grinding noise
Post by: waqr on April 19, 2017, 01:57:20 PM
Just got a reply on the flywheel so this is all good. However, the mystery where the grinding noise comes from still remains.

Someone on another forum told me that he had a similar grinding noise and that he just removed the variator and then assembled the flywheel and fan first and last assembled the variator. He wrote something about that this shifted the crankshaft slightly which stopped his scooter from sounding so nasty.

Sounds like a very strange solution to me, what do you guys think?