04 Yz450f Starting Problems

hi guys,i bought a yz450f about a month ago which was running great till a couple of days ago.basically,i ran it for about an hour and stopped for a bite to eat.when i came to start it up again nothing happened,then the kickstart was stuck solid at the top of the stroke and wouldnt budge at all.after a chat with a couple of guy at the track,i put the bike in 4th gear and pushed it backwards which then freed up the kickstart.the problem is,since doing that the bike hasnt started since and every so often when kicking over i get a bang out the tailpipe and petrol coming out the carb overflow pipe which i assume is flooding.i removed the dipstick and oil was overflowing too.a day later and the oil has finally dropped to normal but still not starting even with a new plug.i'm not very mechanically minded so would appreciate any info in plain terms,cheers guys.

did you try to bump start it? if it starts id get your valves checked.

yeah i did,the bike fired but when touching the throttle it just died again

i put the bike in 4th gear and pushed it backwards which then freed up the kickstart.the problem is,since doing that the bike hasnt started since and every so often when kicking over i get a bang out the tailpipe and petrol coming out the carb overflow pipe which i assume is flooding.i removed the dipstick and oil was overflowing too.a day later and the oil has finally dropped to normal but still not starting even with a new plug.i'm not very mechanically minded so would appreciate any info in plain terms,cheers guys.
The kick starter was probably stuck due to a trapped decompression pin; an occasional, temporary problem:

http://www.thumpertalk.com/forum/showthread.php?p=5314979#post5314979

Your engine oil is over filled, and the level drops over time because it's a dry sump system:

http://www.thumpertalk.com/forum/showthread.php?p=5221903#post5221903

The flooding carb is a problem. Get that fixed and the float level correctly set, and try again with a clean plug.

thanx for the info guys,will have a look at the carb

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