Johnson 15 hp question

[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 down for a few minutes it becomes hard if not impossible to restart unless I wait for awhile. In the bucket the water coming from the pee hole is always cool. Could a stuck thermostat cause this problem?
Thanks in advance to any and all replies.

 

[sutor623]

Re: Johnson 15 hp question

These motors will continue to flow water out of the telltale hole even with a stuck thermostat. Just some food for thought.

 

[sutor623]

Re: Johnson 15 hp question

Also, sometimes when an ignition coil or powerpack is going bad, as it heats up it becomes harder to restart the motor...

 

[HighTrim]

Re: Johnson 15 hp question

Yes perhaps a stuck t stat is not allowing your motor to get to optimal operating temp. Also possible someone took the tstat out, I dont know why guys do this but if this is the case reinstall one.

Regarding your hard start it could be an ignition component as mentioned heating up. You're not trying to use the choke on a warm start are you?

 

[jr.deerslayer]

Re: Johnson 15 hp question

Hey thanks, Nope I'm not using the choke when restarting. If I immediately restart after running it will start. If i let it sit for a few minutes after a run and try to restart its almost impossible.

 

[kbait]

Re: Johnson 15 hp question

I'd bring my jump-gap spark tester and immediately check spark quality when it won't start. Should jump over 1/4" on both leads if good.

Sure sounds like an ignition issue. If you're not getting good spark when you test, search this forum and you'll find detailed descriptions on how to test components (don't start throwing money w/o testing parts!). Also, here's a must-read for anyone owning a 9.9/15 J/E: http://www.sschapterpsa.com/ramblings/Johnson 9.9_15.htm

Good luck!

 

[jr.deerslayer]

Re: Johnson 15 hp question

I'd bring my jump-gap spark tester and immediately check spark quality when it won't start. Should jump over 1/4" on both leads if good.

Sure sounds like an ignition issue. If you're not getting good spark when you test, search this forum and you'll find detailed descriptions on how to test components (don't start throwing money w/o testing parts!). Also, here's a must-read for anyone owning a 9.9/15 J/E: http://www.sschapterpsa.com/ramblings/Johnson 9.9_15.htm

Good luck!

Actually I have the sschappsa article/manual printed out in a binder, it certainly is a major help. I am going to try and run the motor this weekend and will check the spark, thanks...will give update.

 

[the machinist]

Re: Johnson 15 hp question

I think you will find more like about 7/16" spark jump on the later CD ignition motors, while the 1/4" is about all the older magneto ignition motors will produce.

I have to agree it is probably a ignition problem. And usually it will be a coil going bad OR bad grounding under the coil & not the powerpack.