Re: 1974 Evinrude 9.9 won’t idle at low RPMs, need help

[hotpickle]

quote OptsyEagle:

OK. Really sounds like a carb problem. I would get a carb kit. Pull out that welch plug. Pull out that slow speed jet bearing (looks like a very small plastic funnel hidden well inside the slow speed jet). Soak that sucker in lacquer thinner or carb cleaner and then blow out the passages with compressed air. Do this a couple of times. Then insert a new slow speed bearing into that jet. Insert a new retainer at the outer end of that jet. The retainer will seal the needle. You do not want an air leak or you will get too much air as you have already mentioned as seeming to be the problem. One last point. Once you insert the new slow speed bearing do not use anymore carb cleaner on that area. The bearing is plastic and plastic parts do not like carb cleaner.

Thank you for that explanation. Cleaning a carb makes way more sense to me now that I am getting a better understanding of what I am looking for/how the parts work. Sometimes wading through these message boards is difficult because there is a ton of jargon and procedures used that seem pretty basic and mundane to you guys, but as a beginner it can get my head spinning.

Another thing about the spark plugs. So Pappy and FrankR talk about this booster gap. What my assumption was, was that it referred to the gap on the electrode. But the more I read, am I correct in understanding a booster gap is actually inside the spark plug and something different altogether? The reason why I ask this is because I was trying to cross reference spark plugs using:
http://www.sparkplug-crossreference.com … P_PN/UL81J

Reading up on the NGKs, it seems that product codes including an X will have the booster gap (and the NXG BR7HS or BR6HS don’t have that). Is that potentially why the hotter NGK works? So it seems that the cross referencing table might not be perfect matches.