dies after 10-15 min

I bought this Blaster all apart. It is a 1996 it is supposed to be bored 50 over it has after market pipe and a keihin carb. I put it all togther so I am worried about my wiring etc. It is alot faster than my stock blaster. It rips for the first 10-15 that is what makes this so frustrating.
 
Sounds like maybe a restriction in your fuel valve in the gas tank? Maybe plugged? Take off the fuel line at the carb and turn on the fuel petcock. See how good the fuel flow is.
If not, that does sound like a coil or stator issue perhaps.