Home › Forum › Ask A Member › ’73 18hp OMC will not idle › Re: ’73 18hp OMC will not idle
Does it idle OK with the choke part way on? If so, back to the carb. Do your best to spray carb cleaner through all the low speed gas passages – ideally in the reverse direction. Recently on an early 9.9 Johnson, I had to bend the end of the carb cleaner tube at about a 45 degree angle or more, put it into the needle valve housing, and move it around until I hit the sweet spot where it was back flushing into the carb bowl. Of course, the small plastic "bearing" as t is called has to be removed while doing this. It cured the lean idle problem when nothing else did. I was ready to give up! I had a long message string here about that one until I solved it. I also had another 9.9 that would not idle right until I switched to NGK spark plugs. Why this made a difference is a mystery but others have had this happen too – not sure if that will help an 18.
Dave