What happened?

[burst43]

Hey everyone. I use the search, but didn't find what I need. Running 260 mains, stock pilots, 3 clip. FMF Gnarly/Powercore 2s. I put the exhaust on and jetted it as stated. The quad ran great. I rode it 5 times totally approx 10-12 hours. In the middle of the last ride, it started popping. Now it pops, it jerks when riding it, and runs like crap. Hard to start. I changed the plugs. No help.

 

Did a plug chop today, looked like a slate gray color.

 

I understand that it is running lean, but any idea what is causing it? No real change in atmospheric conditions since I jetted it. Choke tube is in place.

 

Any help trouble shooting this would be greatly appreciated.

[ogre03]

What are you running for air filter set up? What about your elevation? It sounds like your jetted lean to me. But if it was actually correct before and and is lean now, look for an air leak first, before trying to rejet.

[banshdog]

Check your compression.

 

maybe your bike was lean the whole time..... like ogre said, need to know air setup and elevation.

[wesw]

try raising your needle to the 4th and see how it runs.

[bansheeseat$$]

Sounds like you developed an air leak.

[sheecandy]

id check to see if your getting good fuel flow out of the petcock

[ellison445]

I concur

 

try raising your needle to the 4th and see how it runs.

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