need some help guys

[YFZ450Ridr]

so i went riding 2 weeks ago on my rebuilt motor and it ran great and i broke it in right, didnt rev it up really high or anything. so then last weekend i took it riding and it started up fine and ran for about an hour then just all at once blubbered down and died then would not start again.

so since then i have adjusted the valves which were barely off, put in a new plug which gets plenty of spark. the gas comes down into the bowl fine and im sure the folats are not stuck.

the motor inside is all fresh so im pretty sure its nothing inside so for now im ruling the motor out, the valves are in spec, the carb gets fuel and the jets are not clogged. what do you guys think my problem is? im at a loss for ideas on whats wrong, what do you guys think? im going to take the carb off and clean it thoroughly, mabye somthing is clogged or dirty?

any ideas, please help me!

[YFZ#426]

like u said the first thing u should do it pull the carb off. Dirt may have found its way into it.

[honda300EXtreme]

umm. is your gas tank vent clogged, and is your fuel line pinched when the bike is put together?

other than that i dont know

[the Z Man]

Its a YFZ... Just kidding, if you have spark and fuel, check compression, timing.
Take your filter off and spray some starting fluid in the carb while trying to start it.
Sounds like its either not getting fuel or timing is off/. Is there a ground wire that may have come off?