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1985 Yamaha 9.9 four stroke start issue

C

capezig

New member
Our local youth sailing non-profit had this engine donated and we're trying to get it running right. I changed the crankcase oil, checked the lower unit oil, changed the spark plugs, cleaned a bunch of goo out of the carburetor bowl and main jet, put in a carb repair kit, set up a tank with new fuel and have it on a good battery with a hose on muffs for cooling water. I have had the carb apart at least 4 times, running carb cleaner/air/phone wire through all the little passages. It will start easily and run only if the air intake is restricted with a thumb controlling the amount of air flow available. As long as the air intake is restricted and adjusted finely with your thumb the engine runs very nicely. If you crank the throttle up to the high end of the range allowed in neutral it will run just fine, but it will not run at the low end unless the air intake is restricted...any ideas on what I'm missing?
 
For other's reference, what I was missing was the tiny hole in the end of the pilot jet and the tiny holes in the side of the main jet...jobs for a very small needle after getting both out of the carb and cleaning the outside crud off with a wire wheel...works like a champ now.
 
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