engine won't start

So I have set the engine onto the mountain bike have checked the spark plug for spark and I do get spark when tested on the outside case. I can get the engine started when I peddle to 20km/h but it wont idle and The throttle needs to be full throttle. If I start at a lower speed I get...

Im just a kid just mucking around in my garage with a motorised bike. The other day I windowed out my piston (a lot) and now the engine won't start. I have a HP carburettor and a very slightly sanded cylinder head. I see people talking about reed valves when they mention windowed pistons. What's...

Hi guys I have a motorized bike and it work fine stock going 27 tops bone rattling tho. But I decided to adjust carburetor and after a few test runs. It bogged out on me! Now it won't fully start. Its like it comes on but doesn't fully get going. Then does studdered bogging as if its struggling...

Norm, I was wondering if you or anyone else could help me out. I have a 80cc Flying Horse engine with a performance carburetor. I got the kit from Bikeberry.com. I am having trouble getting it to start. The bike worked for two days and now it wont start. On the second day the engine died on me...

So. I have put together two of these motorized bikes. One for my friend and one for me. His bike works fine. Cheap **** motors though. Mine was a bust. I have pretty much replaced THE WHOLE DEAL with parts from thatsdax.com. I was happy with every part. I had my jeans get sucked up into my bike...