Starts but doesn't go

[Callum2461]

Ok so I have a 70cc, 2 stroke bike and I have had a few problems with it at the start but I have fixed them all. Anyway I was riding it the other day up a really steep hill and when I was nearing the top it made this noise and just pretty much cut out. I'm thinking I may have blown the magneto because the bike still turns on but nothing happens when I pull the throttle, and as soon as I pull the clutch in it turns off without me having to push the kill switch. The bike seems really weak. I have recently taken the muffler off before this happened because it sounds really good without it but maybe that caused the problem because the exhaust needs pressure? Please help, thanks.

 

[Fabian]

What kind of noise did the bike make when it stopped working?

was it a:

clunky-de-clunk, clunk, clunck, clunk

or

was it a poppy-de-pop, pop, pop, oh bugger it, i don't think i'm going to run any longer, pop and bang...

or

was it more of an asthmatic wheezing, gurgling kind of sound, like a tissue being sucked through a vacuum cleaner pipe,

or

was it more like a wheezing, gurgling, squeeling, scratching kind of sound, like a cat being sucked through an industrial vacuum system, whilst swirling around the inside of a hopper tray; clinging for dear life on a block of polystyrene of ever decreasing size as it's torn to pieces by 4 paws and 20 claws.

 

[dchevygod]

You scored the top end I believe

You should never run a 2 stroke without an exhaust,without back pressure the ring floats around in the ring groove and snaggs plating or a piece of the transfers.

Hard to learn this way but I think you'll run an exhaust from now on. Sorry about your motor.

Try and pedal real fast before letting the clutch out. Give it some throttle and pedal you ass off see if it has any power at all. If it does have some power but not as much as previously the compression is down because of cylinder wear.