01 Yamaha 50hp 2 stroke will not rev.

Pontoon Chuck

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Jul 29, 2009
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I have a 2001 Yamaha 50hp 2 stroke. The boat sat for about 4 months and ran terrible the first time out. could not get more than 2200 RPMs'.
I had the carbs cleaned/rebuilt and the boat idled great. Attempted to get up to speed and the thing caughed out and stalled. Removed the hood and found that the mechanic left #1 plug wire off.
Tried again the next day and boat ran pretty darn good. Not as good as before it sat but still able to get WOT 4300RPMs and 19mph on 20ft pontoon.
Used one tank of gas.
2 weeks later took boat out in the oceat for 10-12 mile ride. started running rough.
2 more weeks, took it out a third time. Ran good for about an hour. Ran terrible at idle after that. Ok with some rpms but lost about 5 mph and could hear some bogging at WOT.
Took it home to rinse, put the ears on it and it idled good. The moment I touch the throttle it cuts out. Cannot get beyond a rough idle.
New fuel 50:1 mixture (not injected) no water in tank or in lines. Filter is clean with no debris. Plugs damp and dark on electrode. Insulator is white. Therefore, mixture looks good.
Somebody help! I paid 300+ for carb work and got 1.5 good uses out of it or about 10 gallons of new fuel run through it.:mad:
 
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