Help needed, blaster not running.

[maverickben]

Hello all, I have an 01 blaster that I have completely rebuilt the engine from the bottom up ported and polished head, FMF pipes bored .10 over. Well I started it up and it ran good so I started brake-in on it, it ran well for an hour or so and then the chain broke and it revved high so I shut it off
and let it cool, started back up put a new chain on it the next day but when I turned it on it ran for a little bit then started to bog down then died, it did it several times and now it will not even start. I have gone through it, it has spark,
and fuel I rebuilt the carb and jetted it to 300. I put on new reeds, it has good compression. I am at a complete loss of what to do! Any help would be greatly appreciated

 

[Larry's Shee]

What does the plug look like? Did you get past break-in and actually ride it? Check tank vent and hose, fuel pecock, clean it and tank, check vents on carb. Do a real comp test and leak-down test. Did you re-torque head and jug after heat cycles? Maybe look at piston when you have exhaust off for leakdown.