Carb popping at idle

[full stringer]

first of all i have a 1984 omc stern drive w/ a 260 hp motor 4 bbl holley. after my boat sat for 4 months (with some stabil in fuel system maybe not enough though) i went to take it out. i dropped her in the drink and she wouldnt start or even turn over very good. so i took it home cleaned up contacts, cables, and replaced starter now it starts and runs fairly steady on muffs but the damn carb pops at idle like crazy and if you quick throotle it it will backfire then back to just pop pop pop continously. dumped the water fuel seperator (and it did have some water and crap in it) and started it again same problem but not really as loud of a popping sound. i was told bad gas or a distrubuter condensor or weak valve spring. WHAT IS THE CULPRIT?????

 

[Bondo]

Re: Carb popping at idle

first of all i have a 1984 omc stern drive w/ a 260 hp motor 4 bbl holley. after my boat sat for 4 months (with some stabil in fuel system maybe not enough though) i went to take it out. i dropped her in the drink and she wouldnt start or even turn over very good. so i took it home cleaned up contacts, cables, and replaced starter now it starts and runs fairly steady on muffs but the damn carb pops at idle like crazy and if you quick throotle it it will backfire then back to just pop pop pop continously. dumped the water fuel seperator (and it did have some water and crap in it) and started it again same problem but not really as loud of a popping sound. i was told bad gas or a distrubuter condensor or weak valve spring. WHAT IS THE CULPRIT?????

Ayuh,... My guess is the Carb has more of that Crud in it as well...

Rebuild it...

A compression test will tell the story on the valves...

Oh,... and check the Firing Order...
A crossed plug wire might also do that...

 

[chriscraft254]

Re: Carb popping at idle

Sounds like timing to me. Have you set the timing? Adjusted the ignition? Might be that its not firing tdc