YZ125 runs like crap

[Troublemaker]

Hi guys i am a new member to this forum and i ride a 2003 YZ125 and when i start up my bike it runs for maybe 3 minutes just fine but then dies, 20 kicks later starts up and will run for three minutes. Its very aggravating, ive tried switching spark plugs with no improvement...i cant figure out whats wrong and i need to get my bike fixed asap before i go out on a thanksgiving trip to go MXing.

Happy Thanksgiving everyone

 

[IndyMX]

Have you checked for sticking float in the carb?

Could be that it's no refilling the bowl fast enough to keep up with the engine, then by the time it gets fired again, it's filled up.

Perhaps you should take the carb apart and give it a good cleaning. And by that, I don't mean just spray carb cleaner on it and call it good.. I mean tear it completely down and soak it. Then blow out all of the orifice's and replace any worn parts.

Once you know it's clean, you can start to diagnose problems.

 

[sharky243]

Definitely sounds like a blockage in the fuel inlet of the carb, fuel line, or fuel petcock off the tank. Pull the access plug off the bottom of the carb and do a fuel flow test. Empty the bowl, turn the fuel valve back on and look for a good steady flow of fuel. If the flow is slow, you have a blockage or a stuck float.

 

[2-Strokes 4-ever]

Definitely sounds like a blockage in the fuel inlet of the carb, fuel line, or fuel petcock off the tank. Pull the access plug off the bottom of the carb and do a fuel flow test. Empty the bowl, turn the fuel valve back on and look for a good steady flow of fuel. If the flow is slow, you have a blockage or a stuck float.

... and if you're real lucky, sometimes this can fix your problem. By emptying the bowl and then letting fuel flow through it, sometimes the spec of dirt can fall out of the now-open needle/seat location. Maybe.

Todays fuel goes bad and varnishes quick. If the bike's sitting for more than a couple months, empty the bowl before storing the bike.