Backfiring out of Carburetor

[Sunken Ship]

'99 4.3GL PWTR

The timing is set and is dead on. Boat runs excellent, except when I accelerate sharply then it pops or backfires out of the carburetor. Rebuilt carb and it is doing the same thing after the rebuild. If I run it up slowly and wait for the ICM to advance the timing at 2500 RPMS then it will take off and run perfect.

 

[Scott Danforth]

you are experiencing what is known as a lean sneeze. no need for a video

you are running out of fuel when you try to accellerate

 

[Lou C]

I might want to do a compression test because backfiring or popping through the carb can also be a sign of leaking/sticking intake valves. The air/fuel mix leaks back into the intake and ignites right under the carb. Do these have an adjustable valve train like the older 4.3s or is it non-adjustable?

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