2002 Yamaha big bear 400
#1
Hi, need help. I've just recently got a Yamaha big bear 400 with a no spark issue, I was told it ran great before it lost spark anyways it turned out to be the cdi box. I have spark now and I've replaced the ignition switch, coil,spark plug, and also bought a new oem carburetor for it,checked all the wiring did all the test on the stator,pick up coil,rectifier, everything I can think of but it runs bad. It will idle fine but when I go to rev it up cuts out and backfires. I've adjusted the air/fuel mixture screw all the way in and out with no change. I'm at a loss any help would be greatly appreciated. Thanks.
#3
It is a oem cdi box, checked charging system, I unplugged the rectifier and still does the same thing. But I will check the brake switch I didn't think about that. Thanks for your help I'll update when I get a chance to check it.
#7





