Johnson 15 hp trouble Losing Prime

[jr.deerslayer]

I have a 1982 Johnson Seahorse 15 hp. In the bucket it runs great, I am able to shut it off and restart it whenever i want. On the water it normally starts good for the first run. During the run it runs very good and will idle good. After i shut it done for a few minutes it becomes a pain to start and i usually have to pull my balls off to get it restarted. My primer ball gets soft after first run and never really seems to get as hard as when i first start. It has always restarted ...Knock on Wood... but never without a nervous struggle. And after it starts it will continue to run good untill the shut down and restart procedure
I have had carb cleaned
New fuel Pump Kit

Any Ideas, Thanks in advance

 

[AlTn]

Re: Johnson 15 hp trouble Losing Prime

a starting point is to make sure your tank is vented properly. I'd suggest running it with the cap loose or off, if possible, and if it's still difficult to restart, check the end of the pick up tube in the tank as the filter on it may be getting clogged. If no change post back..never a lack of ideas here.

 

[bktheking]

Re: Johnson 15 hp trouble Losing Prime

Have you tried to choke it when warm?

 

[jr.deerslayer]

Re: Johnson 15 hp trouble Losing Prime

I have tried to choke when warm but it dosent really make a difference. I have been thinking and just ordered a new fuel tank and all the components(bulb, connecters) I really have no idea what im doing so I thought that this would be a step in right direction. Maybe a air leak or something in old setup. I did try to open the gas cap and noticed that it was cracked real bad and when i held the tank sideways it leaked fuel, so then i figured with all the rain we've been getting maybe its that, but i assume if there was water in it, it wouldnt start at all? The whole situation has gotten me puzzled and is a little disheartening when your going backward in a fast current with a engine that takes 30 pulls to start.

 

[wmconway]

Re: Johnson 15 hp trouble Losing Prime

The soft bulb is probably from a vacuum in the fuel line between your primer bulb and the fuel pickup. Sounds like either tank not venting, pickup blocked, fuel line crimped off or a sticking check valve in the primer bulb. It's good to go ahead and replace all that stuff. But you may also want to pull the carb and clean out the bowl and clean out the filter in the fuel pump. I would recommend a Moeller gas tank - they're built tough with plenty of protection from water getting in.

 

[bktheking]

Re: Johnson 15 hp trouble Losing Prime

A soft bulb is normal, a collapsed one is not, lets not confuse the two. Run it, pull the plugs and check spark and compression. Let's start with the basics. What about cooling, is the block cool to the touch after running it?

 

[jr.deerslayer]

Re: Johnson 15 hp trouble Losing Prime

A soft bulb is normal, a collapsed one is not, lets not confuse the two. Run it, pull the plugs and check spark and compression. Let's start with the basics. What about cooling, is the block cool to the touch after running it?

To be honest I havent checked to see if the block got hot, because theres always a steady stream of water coming out, but I will. The bulb is not collapsed, but soft and when I try to pump it, it never returns to the hardness that i had started with.
I had a mechanic check compresion and it was nearly equal, it runs smooth at idle all the way through the cycle.

Its confusing because in the barrel Im able to restart it first pull anytime i want, just not on the water

 

[ONERCBOATER]

Re: Johnson 15 hp trouble Losing Prime

when in a barrel what is different? water hieght in relation to motor perhaps? fuel tank hieght? look very carefully at these things.... als 1982 engine has fuel mixture adjustment for low speed.... if that is out of whack then your restarts are hell.

Sean

 

[jr.deerslayer]

Re: Johnson 15 hp trouble Losing Prime

when in a barrel what is different? water hieght in relation to motor perhaps? fuel tank hieght? look very carefully at these things.... als 1982 engine has fuel mixture adjustment for low speed.... if that is out of whack then your restarts are hell.

Sean

Well my fuel tank is below the motor(motor on swing set(3.5 ft) cross rail and tank on ground)I've been reading and it seems i may need to go alittle richer on the low speed adjustment but i wont have time to retry untill the weekend.
Thanks for all your suggestions and imputs

 

[bktheking]

Re: Johnson 15 hp trouble Losing Prime

Difference is backpressure and that's about it. The fuel tank has nothing to do with cold or hot start, you prime the bulb to fill the carb bowl, even if the vent is closed it will still run for a couple of minutes. I've owned and run a couple of 9.9/15's in the past and never had to rechoke or reprime a bulb to get a warm motor running. My suggestion would to go back through the carb, reclean and install a kit, do it right and remove the top plug. It sounds as if it's flooding causing you to pull and pull and pull which essentially clears a motor of gas until it refires. Check the float, if it's an original float it will be cork, trust me, I find them from time to time. Replace it with a new style float and set it to the proper height. If compression is in good order, ignition is tip top then it sounds like carb. Look at the plugs too, they can tell you a lot about how the motor is running. Don't bother trying to adjust anything until you get a new kit. Typically i've had to richen to get it running, if it's not sneezing at idle after it's been run, a warm or hot start shouldn't need a needle adjustment.

 

[wmconway]

Re: Johnson 15 hp trouble Losing Prime

My money is still on the fuel supply. Try replacing the fuel line and tank. If you disconnect the fuel line from the engine, does the bulb get harder? Are you running the engine at WOT in the tank as long as you do on the water? If not then it won't form the same vacuum as running at WOT.

 

[cr2k]

Re: Johnson 15 hp trouble Losing Prime

I would sell it, I could never own anything that made me pull my balls off.

 

[Monte1961]

Re: Johnson 15 hp trouble Losing Prime

hahahahahahahahahahaha Pulling my balls off! Now thats funny!