geo wrote on 12/31/69 at 16:00:01:What does replacing the 52.5 jet with the 55 jet do for performance?
The Savage runs lean with the stock jets. The pilot jet controls the low throttle range (idle to about 1/4 throttle ... it continues to supply fuel all the way to full throttle but is basically insignificant above 1/4 throttle)
It is this excessive leaness that is primarily responsible for the backfiring issues.
The mixture is so lean that some of the fuel gets out of the cylinder unburned and collects in the exhaust system, then will ignite later as a small explosion ... that is the backfire.