Only one plug firing

[jamesdeanhfx]

I have a 1975 Johnson 25 hp seahorse.<br />It came to me only getting spark one one cylinder of two. I swapped the output wires from the ignition system, and the other spark plug fired, which indicates to me that the coils are fine, but that only one set of points is getting power. So, where do I go from there ?

 

[DJ]

Re: Only one plug firing

TSM,<br /><br />I'm confused at your description of what you did.<br /><br />If you swapped the spark plug wire only, that tells me you have a bad wire?<br /><br />If your engine is coil equipped, they are under the flywheel-I think. If not, they are on the back of the cylinder head. Your year engine is a little fuzzy to me.<br /><br />Here's a tip, replace both of the coils, if you replace one.

 

[rickdb1boat]

Re: Only one plug firing

Ditto! If one went, the other is probably not far behind...<br /><br />You can get them here or at your dealer:<br /><br /> Coil # 5172 $32.00 a piece.<br /><br />When you say "Output wires", are you referring to the spark plug wires? Had to ask!!!<br /><br />May also be a bad condenser on that one set of points, also. Try the simple and cheap things first...