Originally Posted by bigmatt

I had that happen to me before. I am not 100% sure in my case,I took the fuel filter out,replaced the line,replaced the cracked exhaust seals. I also took out the needles and cleaned the holes with nitro cleaner. this was on the older carbs with out nitrile seals. Engine ran great, then I put filter back on air bubbles,bad seal in filter? I had a jammin x-2 that had the seal on the fuel tank cap go bad that caused same problems. On my mg-66 when it dropped it's nuts same thing. Took out break in shim,put in new plug retuned,still runnin like a raped ape!!! hope this helps.