1986 175hp 4.3L merc won't idle

[harris2520]

I have a 1986 175hp 4.3L I/O mercruiser V6 GM MCM175, Thunderbolt IV, Alfa outdrive. It has been running great but the last time I was out it was a bit choppy so I only crused about 25mph. When I came down to an idle she shut down like I had something wrapped around the prop. I didn't. But I can't run any more except at HIGH RPMs, 1200 or higher. I checked the outdrive lube and pulled the carb (Mercarb 2 barrle)and did a complete rebuild on it. No help there. I replaced the plugs, (which looked OK.) and adjusted the carb as per the manual. After putting it in the water and playing with the idle, mixture, and timimg for two days got the idle back to 700rpm and smooth.

 

[magster65]

Re: 1986 175hp 4.3L merc won't idle

If you posted anything here as a question, try and remember these guys (myself included) have a difficult time diagnosing problems without looking at your boat. Congratulations on a successful tune-up... sometimes a certain problem is disguised as some other problem.

 

[akriverrat]

Re: 1986 175hp 4.3L merc won't idle

you probably eventually got the blockage out of idle jets. lucky.