Yamaha 200 Idle issue when warm, need some tips please

chrismarion

Petty Officer 2nd Class
Joined
Apr 12, 2006
Messages
115
1988 Yamaha 200 ETXG. Back story, had running issues because the previous owner ran ethanol through the outboards so it was a long process of cleaning and rebuilding everything. Cleaned tank, new fuel lines, new water/fuel filters, new on board fuel filters, rebuilt fuel pumps, rebuilt carbs, new NGK plugs, new impeller housing kits and new lower unit oil. This was all done to each outboard to get it back to tip top as I could. I ran one gallon of premix with one can of sea-foam through each motor.

I have searched the forums and found the same relative answer for my problem, but its not helping me. Cold engine fires up with choke and then idles at 600-700 rpms while in a barrel of water with fresh water being pumped in. After the engine gets to operating temperature, which I assume is operating after 10 minutes, it slowly stalls out. I couldn't get it to restart with choke or throttle plates open. After about five minutes it will restart and repeat the process. Now I still don't have my Yamaha manual I ordered for fine tune specs, so I called a mechanic who works on Suzuki, Yamaha and Mercury. He said almost all Yamaha air/fuel screws are 1.5 turns out. So that is where I started before the first crank after the rebuilding.

I have tried 1.0 turns, 1.5 turns and 2.0 turns on each carburetor. Same outcome every time. Idle doesn't seem to raise or lower the rpm either. This was the number one cure for most people with the idle and stall issue. The other was the fuel pumps. It stinks in one aspect because everything other posts contains I have already replaced due to the ethanol issue. Any help would be appreciated. I am hoping some activity will transpire here.
 
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