1980 ezgo backfires

[ttigner]

I just replaced the crank bearings, crank seals, piston and cylinder on my 1980 ezgo. This year used points and condensor, the cart starts and runs great but after a short period of use, it backfires and blows out both seals. This is getting very frustrating, please help.

[crash12888]

When does it backfire? when you let off of the gas and then back on or when it is running along and just does it?
If your plug stops firing while running and then fires it will backfire.
Backfire back through the crankcase could mean timing is off.
Can you give any more details when it happens?

[ttigner]

the first time it happened the engine was cold, i pulled the choke and it started right up while i had the throttle depressed, then bang a loud backfire and it would not start because the seals dislodged from the case on both sides. i pressed the seals back in and drove it around for maybe 5 minutes and again while depressing the pedal it happened again. i dont know what the point gap or timing should be they are both exactly the way i found them.