86 Johnson 50 hp stalls at low throttle

[Jfj1972]

Hey all, i have a 1986 johnson 50hp outboard that stalls when trying to take off in gear, runs perfect past half throttle and up. i have checked compression 135 on both cylinders, spark jumps 7/16 gap, checked fuel pump diaphram and rebuilt carbs. If i catch it just right before it dies i can bump key in real quick and it will pick up and stay running. Also when running on muffs when it tries to die i can squirt premix into bottom carb and keep it running. I have checked the carbs multiple times as it seems the problem is in bottom carb but can't find anything. Any ideas?

 

[juno pierrat]

try turning the idle screw in 1/2 to 1 turn, have you set the floats in carb?

 

[racerone]

Juno------The parts book does not show a mixture screw on an 86 model.

 

[Jfj1972]

I set floats in carbs when rebuilt and have checked them again twice. It almost seems like a low speed miss but comes out of it if you can get throttle opened up quick enough.

 

[juno pierrat]

not mix, idle speed adjustment, in the Cylinder & crankcase parts breakdown, part 51 SCREW, IDLE ADJUSTMENT, at idle should rest on #59 STOP, IDLE ADJUSTMENT
don,t adjust the spark advance screw the one that has a locking nut, just forward of idle adj.

 

[JustWarminUp]

Ever figure this out?

 

[ct1762@gmail.com]

if its stalling, it is indeed most likely the idle stop screw not adjusted for proper rpm in forward gear. I find 700 rpm in forward gear on the water is ideal. stops low speed stalling issues, but still easy on gearcase.