GY6 Strange noise at top speed By mrfredericksen (Read 7,206 times)

[mrfredericksen]

Hi all, I'm new to this site but have enjoyed reading all the good quality posts and reference information.

I have recently purchased a new-ish Chinese GY6-50cc scooter.
Everything has been going good except now it makes a funny vibrating/grinding noise at top speed. It sounds like something is off balance as it goes loud-quiet-loud-quiet. I thought it might be an unbalanced variator so I changed the weights and made sure they all weighed the same, but that hasn't solved my problem.

Any help would be much appreciated as I use the scooter on a regular basis and would hate to have it break down during my commute.

Thanks
Matt

[jjoshua20213]

I herd the same noise. Shredded(Not poped or broke,but shredded!) a belt 3 hours later in the middle of nowhere. Read the same thing the night before about the noises and the same happening to them.... Belts break even on new scooters.

[jjoshua20213]

What fell out as I opened the cvt cover

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[mrfredericksen]

Thanks for the reply, sorry to here about your belt. I have checked mine and it's in good condition. Guess I have to dig further

[Bashan]

I have run into this more than a few times. Look at the centerstand. There should be a little rubber wheel attached to it that rolls back and forth on a little plate right around where the GY6 code is i.e. left lower front of case. If that wheel is gone, which happens a lot, the centerstand scrapes on the bottom of the engine as the silentbloc motor mount lets the engine move forward and back with speed changes and bumps.

[cdoublejj]

My 50cc will do this weird vibrating noise all the while vibrating the whole scooter pretty good when i get at over 40 mph. I don't think they were made to go 49mph and the wheels aren't balanced for that speed or at all. There are some pretty long down hills where i live.

[jersey]

Does it sound like this:



The poster said he changed his belt and clutch bell and noise went away.

I have a similar problem on my 150cc Jonway, although not as bad (yet). It will make a similar noise / vibration at 40+ mph. I can also see a very slight oscillation in the clutch bell when I turn it by hand.