Please please help

[Aaron_dela@#$₩)*%_1989]

I have about 30min on my 80cc 2stroke from happy time motors hong kong put it together few days ago and having trouble with lack of power using 16:1 fuel 98octane thats metric im in melbourne Australia, no one wants to help me all bike stores say illegal ot touching it mate,
Spark plug is black and after 10min of riding it looses power, is this normal because she is new or have i got a problem? thanks in advance if anyone can help me on my 1st post cheers

 

[gary55]

16:1 is to much oil. I know that is what they recommend, but they are dopes. Drop it down to 6 ozs oil in 128 ozs. of gasoline. You may be losing some compression as well if you haven't re torqued your head yet.
With heating and cooling the dissimilar materials expand and contract at different rates causing things to loosen up. Especially so when new. If the head studs are 8mm re torque them to 162 in. lbs. or 13.5 ft. lbs. Use a 1/4 in. drive torque wrench.
You should check the intake and exhaust for tightness as these will have probably loosened as well. Go easy on them. they are easily stripped. Clean the plug, and give her another go. You should notice improvement. Hope this helps.

 

[skyash]

I live in melbourne. I can fix it

 

[KB_UK]

Why give him fuel mixing instructions in some weird american measurement, he's Australian, nobody even know what an "oh zee" even is. 21:1 ratio is understood by everyone

Black spark plug, and losing power after 10 minutes = too rich fuel/air. When engines warm up they need less fuel so the excess is losing you power, and fouling your spark plug. Are you remembering to turn the choke off? If it's not choke then move the clip on the carb needle one notch higher.

 

[sp1ke]

black plug too much fuel / oil genrally try riseing your carb needle a notch droping your needle lower giving less fuel per air ratio in midrange throttle