Logo
FULL SITE MENU

15 hp dies after running great!

M

mrdopes

Contributing Member
Hey folks,

I recently acquired a 15 Hp johnson (1981) and am having some issues with it. She starts up and runs like a top for about 15 mins, then bogs down and dies. After she dies it is hard to restart, and sometimes starts and putters back out again, but after i let it sit for a while i can start it up and she will run like a top for another 15-20 mins then die again.

I have already:

changed fuel pump
new fuel and primer bulb
changed impeller (it needed it done)
brought it to the shop and had them mess around with it and they said she was ready for the water (200 dollars later and she is still not fixed); they said that the idel knob was broke so they fixed it, and changed lower unit oil and prop seal

I just did a compression check and got 110 on both cylinders... is this okay? I have never had an OB before, just in/out boards....so any help would be appreciated. I really dont want to take it back to the shop so i can throw more money at them for nothing.
 
Sounds as though a coil is expanding and losing its capabilities.When it does it again have a timing light or spark tester with, and test both plugs for spark.
The shop tested while it was cool and not expanded.You now can test it when it happens.
 
Will spark jump a gap of 3/8" with a snap you can hear on both cylinders ?????------------------Cold and after it quits-------------Post results of this testing !!
 
it has spark when hot and cold, and as a recent development, it wont run more than a couple minutes now. It will start however if i shoot some pre-mix in the intake.... carb??

should i change out all the fuel line from the tank to the motor to rule out that possibility?
 
when i prime the bulb, i noticed that fuel seeps from the connector (not the hose) where the line hooks to the motor....could it be that it is sucking in air there?
 
Replace the o-ring in there !!-------Or if that is inconvenient replace the fitting , likely air is leaking in and the pump is drawing air instead of fuel.------------Shame that you have spent this much time and money on this if that turns out to be the problem.
 
Back
Top