I am trying to help diagnois a problem on a friends 1987 Suzuki 230 Quadsport. It seems to run fine, yet get the RPMs up high and you can feel the gas spitting backwards through the carborator throttle body. What eventually happens is the gas collects on the air cleaner and it's housing which floods the engine and it will die after about 30 mins of riding. Anyone experiance this before? What is causing it?

 

I experianced a similar problem a few years ago. It turned out that the oring around my needle and seat was leaking. The gas was bypassing the needle leaking around the oring and over filling the float bowl. LT-F250FY QaudRunner-w/Mukuni carberator.

 

I'll try to get to his Quad Sport in the next week and take a look at that issue. Thanks for the idea...I'll see if it works!