Need help ajusting idle on johnson sea horse 15hp 1977

[lunker3501]

Hi everyone i'm new to all this. Just purchased my first boat. The motor i have is a johnson sea horse 15hp motor starts but wont idle. I have snob on the right side for idle but it doesnt do any thing. Please help!!!!

 

[Big flop]

Re: Need help ajusting idle on johnson sea horse 15hp 1977

Try adjusting idle mixture screw, top front of carb.
Start it about a turn and a half open.
Slowly go in then out & listen for change.
If that does nothing clean carb.
Make sure there is spark on both cylinders.

 

[Will Bark]

Re: Need help ajusting idle on johnson sea horse 15hp 1977

That idle knob on the side of motor is nothing but an idle stop whch is not going to help you right now. If big flop's suggestion does not help you will have to rebuild your carb with a kit; make sure you remove welch plug on top of carb and get the idle circuit holes absolutely clean and blown out with compressed air. That is where your problem is most likely. Good luck.

 

[lunker3501]

Re: Need help ajusting idle on johnson sea horse 15hp 1977

Thanks, whats the best way to check for a spark in both cylinders?

 

[lunker3501]

Re: Need help ajusting idle on johnson sea horse 15hp 1977

Thanks

 

[Will Bark]

Re: Need help ajusting idle on johnson sea horse 15hp 1977

Check for spark using a spark tester from Auto Zone or O'Riellys or NAPA should be about $7-10. Set it a 7/16"; bright blue spark with a "Snap".