70 johnson stalls low speed

[sat1962]

Hello fellow boaters . My problem today was this when headway speed between 1000-2000 rpms she sputters and dies.I rebuilt carbs cleaned them twice .Its a 70 johnson 1988 new fuel lines new gas tank fresh plugs and fuel When wide open throttle it sluggish getting up to high speed but will get there and run fine at 4000- 5800 rpms.any advice much appreciated.forgot to mention spark test was fine and compression was good

 

[ob]

Re: 70 johnson stalls low speed

With the controls in neutral position insure that the carburetor linkage roller is exactly on center aligned with the scribe line on the fiber throttle cam and "just touching." This will insure that the carburetor flaps are in synch with the spark timing advance and are not lagging behind or ahead.Also insure that the timer plate 'under the front flywheel area advances smoothly all the way to the rubber stop when advancing the throttle controls from neutral to full throttle.You'll need to have someone spin the prop while shifting when the engine is not running to do this so as to prevent shift mechanism binding.

The above recommendation is assuming that there is indeed no fuel restrictions present in any of the porting or fixed orifices of the carburetors.

 

[sat1962]

Re: 70 johnson stalls low speed

thanks for advice ill check that .I .rebuilt and cleaned carbs but i think i goofed on something .There was 2 gaskets in the carb kits one was diffrent than the one i was replacing so i thought it might be kit 4 more than one type carb but i read somewhere u need to use both gaskets between body and bowl .Would one gasket being used have adverse affect on carb function?