Re: ’73 18hp OMC will not idle

[johnyrude200]

It will run OK with the choke 1/3rd closed (so not a huge air restriction). This is at 3 turns out though…haven’t tried to mess with it at the recommended 1 turn out. IMHO that factory recommendation is not always true anyways for these motors.

The 18 and 9.9/15 carbs are totally different. The 18 carbs are much simpler and generally forgiving so unless I’m missing something obvious here (which could be the case), the low-speed jet is very simple; a pickup from the outside of the carb (which is a big hole easy to flush), the low speed needle, and 3 tiny bleed holes which feed fuel at low speed. I pulled the welch plug to double check they weren’t clogged, and already replaced the 2 low speed plastic bearings/seals.

Again – I could be missing something here but it is clearly running lean.