Bike will not start

[BigMatt]

Hey everyone i just had a top end rebuild on my 1989 honda cr250. I can not get my bike to start it has fuel,spark,and great compression.The spark plug is not fouled and the top end rebuild was done by what he calls himself a proffessional. The bike has always had the problem of fouling plugs like 10 minutes of riding we have set the bike up 32:1 sometimes it backfires sometimes it dosent.The air screw is set at what its supposed to be.Can anyone help me plz thanks.

 

[overbore]

Sounds like a spark problem to me or a ignition problem or carb,
because of the back firing.Does it kick back sometimes when trying
to start or is it only when it gets hot,it might be a coil.Need more
tests or info.

 

[MikeT]

I bet you sheared the flywheel key. If you did, it is pretty cheap to fix. Just pull the flywheel off and replace the key. I bet that is the problem.