Primer Solenoid

stach1024

Cadet
Joined
May 10, 2010
Messages
6
I have a 1985 Johnson 50HP. Every time I push in the key to prime engine the 20 amp inline fuse blows. I put a new primer in and still does the same. It starts and runs great when primed manually. Could this be in the key switch? Thanks for your help. I need to go fishing.
 

bobjoe1

Petty Officer 3rd Class
Joined
Dec 29, 2009
Messages
87
Re: Primer Solenoid

I had same problem and took it to the boat shop and they couldn't find anything. So by accident one day me and a friend were checking it out and had the motor cover off and I just happen to have been looking right at the primer solonoid when I pushed the primer button and I saw a puff of smoke and there went the fuse again. The little wire going to the primer had worn through on the back side and was creating a short. This ruined many a fishing day and just blind luck found it. Shorts are very difficult to find. Good lick.
 

milmat1

Petty Officer 2nd Class
Joined
Apr 29, 2010
Messages
137
Re: Primer Solenoid

YEP!! The wire to the primer (or at the primer) is shorted to ground...So when you hit the button you are connecting 12VDC straight to ground...
 

jtexas

Fleet Admiral
Joined
Oct 13, 2003
Messages
8,646
Re: Primer Solenoid

Shorts are hard to find if you rely on blind luck. But if you resort to drastic measures, like maybe methodical troubleshooting with a suitable tool such as a 12 pound hammer, or digital multimeter (about $25 at walmart in the automotive aisle), you can track it down.

Sorry, couldn't resist... ;) To answer your question, yes the keyswitch could have developed a short between the C terminal and ground.
 

ezeke

Supreme Mariner
Joined
Sep 19, 2003
Messages
12,532
Re: Primer Solenoid

Disconnect the primer solenoid at the bullet connector on the engine and then push the key in. If the fuse blows, it's not the primer solenoid but something between it and the key switch.

If you have accessories running off the ignition wiring and use the primer solenoid and the starter at the same time, you can easily overload the fuse.
 

stach1024

Cadet
Joined
May 10, 2010
Messages
6
Re: Primer Solenoid

Thank to all who responded to my question. You were all right. I'll be fishing tomorrow.
 
Top