New engine has no power

Sidewinder Jerry

Well-Known Member
Local time
7:38 PM
Mar 14, 2011
Rockwood, TN
I'll be honest. My daily drive has a 142f it has a 525 rear sprocket and tops out about 23-25.
I figured if I bought the same engine I'd get a bit more speed out of the 36t rear. But I didn't take it to account the gearbox. I didn't realize that I made such a huge difference. Not sure what's on my micargi I bought it the customized it myself so the gearbox and the ratio is a mystery to me it runs nice it pulls from dead stop and flies up hill so I wanted to 4 stroke my other bike cuz of all the problems with the 2 strokes. I thought it would be as easy as buying a kit and slapping it on. So not the case. I'd just like the thing to be rideable. A speed in the 20s is fine. But I can't change the sprocket on the rims cu when I bought them I had a failure that nearly killed me(thanks bikeberry) so I red thread locked the bolts in. At the time I didn't thing I'd be taking my beloved yd off of it for a 4 stroke but my micargi runs so good I thought I was doing the right thing. Idk what I'm going to do now. I got Alot of personal problems weighing in on this project too and I'm basically screwed. There's literally no more money to fix or upgrade. So it is what it is I guess
First, you need to figure out which gearbox you have. If it's the BB gearbox you can get a 13t sprocket fairly cheap. If it's the other one then you're going to need a jackshaft with a 17t and 10t sprocket on it. Either of these setups will get you a level ground top speed of around 28 mph.