1986 Yamaha problems

[Harmanoff2]

I’ve been having an issue with my 50hp motor lately. I got some water in the gas and put iso heat in the tank then pulled the drain plugs on the carbs and ran a bunch of fresh gas thru it to clean out the water. Well it runs great at full throttle. But when I start the boat then put it in gear it dies unless I give it enough gas. I noticed when the lid is off it will idle fine and not die. When the lid is put back on the motor does within a few seconds. Is there something clogged in the lid somewhere that pulls air in? I’m at a loss. It ran great before the water got in it but the problems kinda snow balled after it seems.

 

[w2much]

Now try fresh fuel through a fresh tank and line. See that the fresh fuel has reached and filled the carburetor bowls. You have junk in your lines and filter and maybe your carb. You also have water in your fuel. Get the old fuel out of the system and start over. As for the cowl, of course it vents. If it is not venting fix it.