Can`t get my Johnson 65 hp to idle in the water.

[Sheltering]

I have a 1993 65 HP Johnson and I am still unable to get it to idle properly.

I rebuilt all three carburetors, (found one float valve was sticking - replaced all three), I removed and cleaned the fuel pump (it seemed to be in very good condition), I removed the fuel primer solenoid and discovered a crack in the plastic head. I replaced the head and then motor would start every time and idle in the driveway with the water muffs on. When I put it in the water however, it would not idle. Motor seems to work good on the water at higher speeds, but will not idle. I also noticed when idlying in the driveway that only one carburetor would respond when I adjusted the mixture screw. I would screw it in until the engine wanted to stall, and then I would back it out about 1/2 turn. For the other two carbs, I can screw the mixture screws in all the way and nothing happens, the motor continues to idle.

I would appreciate any help.

 

[Fleetwin]

Re: Can`t get my Johnson 65 hp to idle in the water.

Did you use OEM rebuild kits?

Did you check the carburetor bowls for flatness on the mating surfaces?

I think you may you have an air leak somewhere. Either at the float bowl area, , the mounting or the throttle shafts.

 

[Sheltering]

Re: Can`t get my Johnson 65 hp to idle in the water.

Thanks for the quick response. Yes, it was OEM kits. I feel certain that there would not be any leakage at the mating surfaces, either at the bowls or mounting. Do you have any suggestions as to how to check the throttle shafts?