Just wondering if anyone has compression tested a similar bike (or any 125cc for that matter). I have not been able to find any test info. specific to a 125. Mine is coming up at 110PSI. The bike is stock. My buddies CR125, is coming up at 118PSI.
So I am wondering what is good and what is not? Does 110PSI mean it is time to re-build the top-end??
yes it does. when my KDX didnt want to start without being pulled or rolling it downhill i thought it was the topend and the guy at my local yamaha shop said topend also. but i did a compression test on it and there was 153PSI.. but he said it should be between 120-125 PSI. but 110 seems a little low. i would rip the topend down and inspect it.
Im pretty suprised that it still runs at 110 PSI. My RM125 quit running at about 120-125. Its should be atleast 140 - 200+, but over around 200 or so you will probably need race gas and what not.
what kind of tester are you useing, the accuracy of cheap testers is questionable, a schrader valve in the head of the adapter, and the correct length of threads is pretty vital.