Re: FW: Popping back through Carb

[Carmods@aol.com]

One possible cause of "Popping Back" is not enough clearance in your valve 
lifters. The following is copied from Crane's Tech Tips.

"With excessive preload, as the engine RPM and oil pressure increases, the 
hydraulic mechanism will pump-up the pushrod seat. This will cause the valve 
to be open longer and the lift to be higher. This will decrease the cylinder 
pressure, lowering the performance of the engine. If the preload is excessive 
it may cause "backfiring" from the engine."   

                                                 John Logan