Can you turn it over manually?
Did you check valves?
Did you install anything different than just a big bore kit?

More details are required to help you start trouble shooting

 

valve job replaced the exhaust valve with steel and springs 100mm kit the auto decompression seems to be working put a dial indicator on it to make sure , doesnt seem to want to roll thru the compression once in awhile it fire up but die quickly seems to be every stroke it stops starter wont spin it over almost like there is a issue with the starter or related parts but its new.

 

Did you make sure the timing was correct. using the inspection hole and the dots on the cam.

Why did you only do the exhausts and not all of them? Also check the battery for amp load instead of just voltage.

 

the exhaust were the only ones that were bad the timing is on ill check the amp load

 

What does VCC stand for im testing sensors and the B/Br wire is shorted to ground except when i unplug the ECM

 

VCC normally means 5v