Problems with power.
I recently rebuilt my engine like 5000 miles ago. I have started to have problems with the engine...It seems to be loosing power...it studders when you first accelerate...then from 45 to 55 mph it jerks around...giving the engine a generous rev, it backfires out of my intake. I was just wondering if anyone knows what this is. Someone told me that it may be a piston ring because even though i rebuilt the engine, i only changed one piston, the main bearings, the crank and the piston rings.