15 mph top speed with an 80cc engine

[SomeGuy]

Steve

Very helpful! I have ordered both a new muffler and a gasket kit. I'll try everything when I receive them. My engine is simply leaky all over, so I completely agree that I'll need to regasket the thing. The carburetor I'll definitely be checking out as well since it is easy that more junk got into it since I have been riding it hard (on dirt, slush, ice, in the rain, uphill, downhill, etc.) I'm having a lot of fun with it lol.

I'll update ya guys after I fix it up. Thanks again

SomeGuy

 

[sbest]

Yeah, I love mine. Really opened up the distance I can bike in a day. My bike is caked in mud too. We got 8" of snow in the past few days so it has put a damper on the riding.

There is a principle in troubleshooting to put all that you can to "as designed" condition to rule out problems and things interfering with each other. These are a wonderfully simple motor to learn on. A whole engine teardown can be done in an hour with a handful of tools. The only specialty tool is the puller that was supplied with the engine. While at it, I would highly recommend sanding your head and cylinder gasket surface level and look at my posts about squish area and gap for better performance.

Please write to tell us what worked.

Steve

This compares a stock head with the sooty modified head. Note the band just inside the gasket surface. This has increased from 0.100" to 0.300" and is now 0.038" from the piston.