I have a 99 300 4x4 that was running beautiful, then all of a sudden it started spitting and sputtering. I changed the plug and it ran fine for about two minutes then started acting up again. At first I thought it was a fuel issue so checked for water in the tank, clogged filter, cracked fuel line, dirt in carb. Everything checked out fine. I did find the diaphram in carb was ripped so I replaced it. Machine starts and idles fine but as soon as you give it some throttle, it bogs down and shuts off. Finally figured out that the plug is fouling within a couple minutes. I am getting very frustrated and have sunk a lot of money into the machine in the past year. Any help would be greatly appreciated.

 

The "choke" plunger isn't hung open is it. Also, is the float good?

 

may have some stuff floating in the carb. may need to clean the carb and check the gas tank also for dirt or water.