I have a 641 ford with 134 engine, just completed rebuilt engine about six month ago. It was running very good. I park it in the shed to clean up the ten. It sat there for about three months. Last wk I decided to use it for some hole digging When I started it up it began to pop and back fire in carb. First thing first, Checked Timing ok right on, check point they were clean an set @ .025, check plugs they clean and set @ .025 So next check compression all were 100-120 next check carb to make sure it wasn't set to lean.
all help will be appreciated