I've got a buddy's 1988 bayou 300 that I can't figure out what's wrong with it. This has always been an intermittent problem. It starts and idles fine but whenever you give it more that maybe 1/3 throttle it starts loading up, backfiring, losing power and fouling plugs. He took it to the dealer and they replaced the voltage regulator, which was bad, went through the carb and put a new cdi on and it ran good. When they told him the price he told them to take off the cdi and he would replace it later. Well they called back, it was still running good with the old cdi on. We got it, rode a day then loaded up and headed to the woods. Got there and same problem. I'm stumped, it seems like a wiring problem to me, like the ground is bad or something. I always thought a cdi was either good or bad. Anyone got any ideas on what I can do or check?

 

check the slide in the carb, mine was worn out, it would idle fine until you gave it some gas and then it would load up, had to replace the carb.

 

Went through the carb and its good. I'm thinking timing or valves. Any more ideas?

 

did you ever solve your problem, mine is doing the same thing now