Vibration
 

Hey guys! I'm new here. The names Dan! Anyways, I live in Dominica and just purchased a Chinese scooter. More specifically a Jieda qt50 with a 1P39QMB engine. It has under 500KM on the speedo, but I purchased it with a broken speedo cable so i'm not sure of the true mileage. I do know it's not more than 1000 miles though. I've changed the engine oil and CVT oil. It runs well and I have no problems other than a vibration coming from the drivetrain around 30 mph (GPS verified) It feels as if it's about to implode! I know these little scooters aren't rated for much more than 30mph but to my understanding it shouldn't feel as if it were going to blow up. Any suggestions? Also, flat ground speed is average about 20mph which seems a little low although I am a bigger guy at 255. Again, it runs completely fine otherwise. Any suggestions? Also I am SURE it's not tire vibration.

I have not encountered even 1 of these scooters where the tires have been properly mounted. They all squirm down the road, the tires wear uneven and cause vibrations.

to test for vibrations, get very familiar with its 'feel' , place the scooter on the center stand, start it and rev the engine trying to recreate it. If you do recreate it on the center stand then the front end is eliminated.

observe the rear wheel to see if it is squirming, and how bad.

if you overfill the oil, it will cause vibrations.

btw.. even a stock 49cc can go faster than you state with a little tuning

My stand is broken unfortunately, but i will try and find a block of wood. Although I am fairly confident it's not the tires. The whole scooter doesn't vibrate and I can hear the engine revved extremely high like I am at the maximum of my RPM range. I will still try the above test though!

Oh and also, I double checked both oils yesterday, I wanted to ensure there were no leaks.

So I took it for a ride today and when I got into the "vibration" zone, I played around a little. When I let off the throttle the vibration stops. When I get back on the throttle it starts again. ALSO, When I just kept going I began hearing a squeaking sound..

Hey guys, I opened my CVT cover and there was quite a bit of "belt dust" in there. for a scooter with under 1k I didn't there it would be this dirty in there. Is the belt pretty worn?

When you got the scoot supported, was the rear wheel/ tire squirming? How were the engine support bushings?