Pops above 3200 rpm

[nolddk]

I just rebuild my engine , bore , new pistons, bearings . Now when i drive it ,it makes like a popping sound above 3200 rpm , and thats in all gears , changed the air cut off valve and put larger main jets in to solve the issue , no change there . Hope for a few good ideas , the mechanics here in Denmark have none

[CrystalPistol]

Return carbs to stock specs first.

Check you cam timing marks closely.