Hello, about a half a year ago I got a 150ccD tao tao atv. My brother got himself one as well. My brothers sounds smoother and the acceleration feels like BUTTER! But mine sounds really loud, it sort of vibrates and sounds higher pitched of a rev(Like it is over reving) when going fast, and it almost sounds like its gonna blow. I have tried tightening everything and I am changing the oil right now. But does anyone have any ideas? Because I think there is more to it than just because it is Chinese. Thank you. and I hope I fix it

 

Are those cvt or do you shift manually? If it's a cvt auto, sounds like you need to open the cvt cover and run it with the rear wheels off the ground to verify proper operation.

 

Any rotating mass (crank/axle/wheels/clutches) could be causing the vibration...your explanation with the sound would point me to the motor/clutches first...


MPDano's suggestion is a very good place to start as it might help you isolate the noise/vibration...

 

It almost sound more like an over revving sound like it is going to fast. It gets over revving and high pitched when going fast or down hill. Any ideas

 

High pitched sound from where???? We really need some isolation of the noise...if the noise only happens when driving it then it could just be a wheel/carrier bearing going bad...


If you lift the rear end and run it that should help you pinpoint the area making the noise...

 

I figured out the problem. I just need to change the size of the sprockets. Think of it this way; if you are bicycling really fast on an easy gear then your legs will be moving too fast. My atvs reaches a speed then over revs. If I make it a harder gear it will be a slower acceleration but can take way more speed. Cheers

 

Ok, by the original post, it sounded like you both got identical quads. To include gearing. Glad your sorted.

 

All's well that ends well...

 

Maybe. If it's a CVT then he needs to get in there.
"My atvs reaches a speed then over revs."
IMO, if it's over reving it should be going faster..Right?

 

agreed...sounds like belt slippage...but if he's happy with the gear reduction then he's happy...