backfiring through carb

[andrewz9876]

I have a 85 mercruiser 260 i have a backfire through carb issue boat sits and idles fine when i take the boat between 1200-1500 rpm i get an intermittent backfire after that its fine.I drained the fuel and thought that would fix it and it didn't any suggestions???

[BUIZILLA]

accell pump plunger

[joseph m. hahnl]

What carb do you have? Your saying once you get buy 1500 rpm the problem goes away?If you leave it between 1200 and 1500 it starts popping through the carb?

Sounds like the primary float bowl is contaminated.

[MOP]

Another possibility is wires, I ran into a similar issue years back same RPM ranges. The engine had just had new plugs and points having just come out of storage. I ran the boat on another tank suspecting poor or contaminated fuel, rebuilt the carb, did vacuum checks you name it. Decided to try a set of wires problem solved, I surmised that in that RPM range getting onto plane was the heaviest load and the ignition just would not carry it.