Hello all, thank god for places like this. I picked up a 91 blaster that needed some top end work. Had the cylinder bored, put in a new Vortex piston/ rings/ gasket/ plug/ reed valves. Rebuilt the carb. Started it and it ran fine. ran it around a bit all good.. Second time out. Can't get it to idle. adjusted air/ and Idle screw and it back fires as well. Lokking for any and all opinions on what it could be. I really don't know why 2-strokes back fire!!!

Thanks
Chris

 

A lean condition usually is the cause of your backfiring. First, check to see if the intake and exhaust are all still securely fastened and there are no cracks or leaks. Since it originally ran fine after reassembly this may be the problem. If that doesn't pan out, check the pilot for dirt or blockage. The next step is to up the jetting. Initially, my bet is that something was either tourqued down to much and broke or wasn't tightened enough and has worked it's way loose. Good luck and report back when you get her fixed.