If your blowing fuel out of the carb, not sucking it in then your reeds are the problem.The reeds are suppose to close on the compession stroke. Sounds like you need to find someone to work on it that you trust. Or take the plunge like many here and do it yourself. Theres plenty of information on how to work on them if you look. All of the motors are basically the same, so find an shop manual and get after it.

 

http://webzoom.freewebs.com/miniatvs/Viper%20Manual.pdf Here's a manual for a Eton Viper 90

 

Did we ever figure out who actually makes the motor?

 

its a yamaha just like eton atv's

 

I still think you have a compression problem. I doubt the engine still has 120 lbs. of compression if it is a few years old and has had no motor work done to it. A burnt piston will cause blowby. The motor will run with low comrpession, usually caused by worn rings, it just won't run very good. I have a parts and service manual for this bike that will help you if you decide to do the work yourself. Earlier in this thread I posted where I bought the parts to repair my bike. If you want a copy of the pages you need for this repair, leave a post on how I can get ahold of you and I will get you a copy. I will check back in a day or so.

 

Linhai

 

Bandits3 - I would need whatever parts and services pages they have on replacing the piston and rings. You can email me at hawkdriver@hawkdriver.com - thanks in advance. How significant is this job? I am planning on digging into the engine this weekend to see if the cylinder has 'scoring' on it as well. I'll take whatever pictures I can and post a link here once I get to that point.

 

Bandits3 - I re-read your earlier post about the WRH racing site for the new top end. I'm calling them tomorrow about the same setup. Do you have any reccomendations on this mod? Thanks.

 

Hawkdriver, check your e-mail.

 

Hi, i am new here, but i have been searching for forums about Sundiro's. I have a Sundiro Sunray 90. It was ok. But after a few years it started to really shut down. It wouldnt start good. and Something was always wrong. Well i am saving up to get a new 4-wheeler. So i just wanted 2 know if any1 needed anyparts for their sundiro sunray 90. if you need anyparts, i will be glad to sell them 2 u. (at a reasonable price that is). I will be on almost everyday to come check. In my profile on this website, i have a AIM screen-name. if u need to contact me plez do. and if you dont i believe my email address is in there too. Thanx 4 lookin.