Johnson 14spl fuel starvation

[LittleboatPhil]

Greetings all, long time reader first time poster. I’ll get right to it, a fishing buddy of mine has a 1988 Johnson 14spl that has got me stumped. Engine starts on 4 or 5 pulls, runs strong, idles down nicely, then overrevs and stalls. I pulled the hose on the primer circuit and it takes about 8 pulls on the plunger to get gas to come out which makes me think float bowl is empty. Primer bulb stays hard while running, and squeezing when it starts to lean out doesn’t stop it from stalling, in fact gas will start to drip out the carb body but still stall. I didn’t have time to pull carb while I was visiting but does something as simple as an improperly installed float/needle valve sound like a possible culprit? It will probably be coming home with me to work on this week, hopefully this thread will help someone else since there is such a sparsity of info on these 14’s

 

[racerone]

This model " 14 " HP is nothing special at all.-----It is the same powerhead as the 9.9 / 15 HP family.-----Built with an adapter to use the older 20 / 25 midsections.----They likely had a warehouse full of those midsections to get rid of with some marketing !!-----Check / inspect carburetor and fuel pump for a blockage.

 

[LittleboatPhil]

This model " 14 " HP is nothing special at all.-----It is the same powerhead as the 9.9 / 15 HP family.-----Built with an adapter to use the older 20 / 25 midsections.----They likely had a warehouse full of those midsections to get rid of with some marketing !!-----Check / inspect carburetor and fuel pump for a blockage.

I read somewhere that they were just a 9.9/15 power head with a 20+ lower, good to know that’s the case! Thanks

 

[LittleboatPhil]

Back again with some long overdue progress reporting.
I ended up with this motor in my possession, and thought I had it beat.
It was combo bad fuel pump, and BOTH cracked upper and lower carb bodies. All have been replaced and everything seemed fine until real time lake test.
First time out, motor started on first pull but was smoking like crazy (seafoam and stabil added to tank, assumed it was just decarb) and wouldn’t rev above acouple thousand at full throttle. Seemed flooded. After about 30 seconds it leaned back out and we were off, pulling 17mph at about 5500 rpm (cav plate is low, has since been shimmed). Ran a lap around the lake, killed it, restarted first pull, idled smooth, all is well.
Next outing, same story except it did NOT lean out and eventually stalled. Restarted after 15 minutes and enough pulls on the rope to leave carpet burns on my knees. Ran a lap about 1/2 mile, killed it, restarted 2nd pull. This time I left it to idle and within 20 seconds began to bog and smoke, but would lean out in gear at full throttle.

Carb has been soaked in Gunk, sprayed, and compressed aired

Float set to level upside down, new seat and needle from kit

Haven’t checked compression but spark is very strong (well over 1/2 inch open air)

Any ideas here? Thanks fellas.

 

[LittleboatPhil]

I should also add that the listed replacement top cap for carb has different passages under it and the cam follower is molded into the cap, as opposed to the one on the motor wherein the follower is attached via a bolt. Could it be as simple as a mid adjusted low speed needle? Will try to replicate issue in tank.