As LynnEdwards suggested, the enricheners go bad commonly. Other common issues for these syptoms are bad crank seals, improper jetting, incorrect carb adjustment, incorrect float height adjustment, fuel line/filter restricting flow (make sure to check flow at the fuel line just before it enters the carb) or simply a faulty carb.

I believe Eton has instructions on thier website for carb adjustment: ETON America.

Parts are relatively easy to find for this platform, we carry several replacement and performance parts for 2 strokes. We also sell OEM Eton parts, so feel free to contact us if you need assistance locating something.