70cc bogging down at full throttle?

[NorCalVince]

I ordered my motor kit from Wish, and it came with instructions. I've also been an automotive technician for 25 years. That doesn't make me a 2 stroke, small engine expert at any means, but I know from experience that it's usually best to follow what the manufacturer recommends. The instructions that came with my engine says during the break-in period, run the fuel/ oil mix at 16;1, and not to go faster then 20kph. The break- in is the 1st 100 miles of riding. After break-in run the fuel/oil mix at 20;1. Hope this helps any disputes.

 

[Eddie2Stroke]

My bike started doing it as well, just recently at 200miles breaking period oh Also it's a 100cc kit, it gets to 31mph and starts bogging to 29 then back to 30-31.. mind you my kit required a 5.5oz first tank break in and 4oz after.. I'm doing a 6oz then 4.5oz but I also accidently got. Gallon of 87 not 91, I pressed 91 and the shell station pumped 87... I just went with it but tonight I'm getting 91, and possible some octane booster or carburetor cleaner Lucas brand.

Also I broke it in the first tank going 18-25mph, I got it on the 2nd tank to max at 40mph but that for a slight test, engine still ran normal, on NT carb with stock exhaust I use Lucas 2t Semi synthetic oil, no oil marks only from the top of the 1 piece cylinder by the spark plug it seems. Spark plug has a Brownish/tan look dry not oily, on the 3rd slot of the 5 carb pin.. thinking it's running a slight lean or the low fuel quality is making me bog down.. I will verify if the New fuel changes my bogging.

 

[Eddie2Stroke]

Im back, I put 91octane and it got speed up to 34mph still bogged, after riding found my carb choke lever flopping around, not alot but noticeable. I tighten the bolt holding the lever by the filter,also moved the carb pin from #3(0ut of 5) into the 4th(richer), now I got it to go 40mph again but it still kinda bogs just a bit, maybe my clutch plate is loose or pads got worn just a bit, allowing play inside the plate. It has 240miles as of today, so maybe it's still breaking in.. will test more and adjust parts and try lock on the suspects.

 

[Eddie2Stroke]

Oh also spark plug was changed and the oil marks went away on top.i used the NGK b6hs, changed with another B6hs, it seems It was gap to close, the new one is gapped to .32 the oily one was at .22 to close together.