Yamaha ATV backfire, bogging, stutter, carb problems

ALL ATV owners that are having carb problems please note!!!

Coil bad grounds can lead you to misdiagnose carb problems. I spent months trying to fix my carbs when it was fine after my first rebuild. It took a very long time to diagnose my Yamaha because so many people chime on about bad fuel mistures and clogged carbs. After taking my carb off a hundred times and cleaning and dipping and changing jets and welll you know the drill, I found that my problem was a bad ground wire. I had spark all along but it was weak spark causing the motor to backfire, sputter and run like crap or mysteriously stop after running great!

Check your Coil lines, look for a short or broken ground wire in your harnness or a bad ground to the coil. I just went through total Hell taking my carb off 100 times. I had a half broken ground wire to my coil that cause weak spark and all the symptoms everyone describes. The weak spark made the plug appear to be fouling from a rich air fuel mixture. It had all the symptoms of a bad plugged or misadjusted carb but it wasn't! Save yourself a huge amount of headaches. Just because you have spark does not mean there is a bad ground or broken wire causing the problem.