No adjustment on the float. Probably not your issue. First, yes there should be a O ring inside the round connector where it hooks to motor. If it is missing or damaged you could be sucking air around it causing your problem. Even though you got cleaner to go through the jets you might still have some clogging. I would check the connection first and make sure it is not leaking. You should be able to check by installing a with out holding it in place pump up the bulb as hard as you can then let sit and check for any fuel leaking around it. Once that is eliminated, put just a couple of gallons of gas in tank and dose it up real good with some SeaFoam. Then run it for a while in drum or on muffs. Nothing more than a idle. After about 15 min shut it down and let sit over night then run it again. Let sit then take back to the lake and run it and see if that dosn't help. You never want to rev one on the muffs cause it can run away and tear up motor, running one in drum at to much rpm can heat up the water and cause motor to over heat.
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Charlie Weaver USN/ENC 1965-1979