Engine won't idle

MKmedic

Cadet
Joined
Sep 27, 2013
Messages
18
Hello All, I'm newish to the forum and I have a question about an idling issue on my 4.3l mercruiser V6 with a Mercarb 2bbl carburetor. A little background... boaught the boat 4 years ago used and it ran fine, no issues, since then I replaced 2 exhaust manifolds, fuel pump, carb, electrical. I got the carb 2 seasons ago at the end of the season, ran it once last year and it ran great!! Took it out last month and had an issue with it stalling below 2000 RPMs. I figured there was gunk in it so I cleaned the carb the best that I could without taking it apart and rebuilding it (used 2 cans of Berrymans). Still sounds like it's starving for fuel. Haven't touched the idle screw yet to adjust the leaness of the fuel. Replacing the fuel line from the carb to the fuel pump (it had a fuel leak and found it was cracked) haven't really touched the throttle screw on the side yet only to get to 2000 RPMs... besides a year down and rebuild of the carb... anything else I can consider looking at? I'll post a pic of the carb tomorrow if you guys need it. Thanks for all the help I greatly appreciate it
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
52,227
Took it out last month and had an issue with it stalling below 2000 RPMs. I figured there was gunk in it so I cleaned the carb the best that I could without taking it apart and rebuilding it (used 2 cans of Berrymans). Still sounds like it's starving for fuel.

you did NOTHING by not taking the carb apart.

there is no magic mechanic in a can

you need to pull the carb apart. soak it overnight, then clean out the passages

I use both spray carb cleaner and compressed air on each passage. I also make sure I can pass a wire or fishing line thru each passage
 

MKmedic

Cadet
Joined
Sep 27, 2013
Messages
18
Thank you for the advice... I ordered the rebuild kit for carb and hopefully it will be here soon. I've never rebuilt a carb before so this should be interesting....
 
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