coil wires

[Scott Sutphen]

I have a high end cough on my 1985 Johnson 120. I have changed plugs and cleaned carbs. It will run fine one day and then cough the next day. I noticed one of the coil wires was a little corroded on the plug end and noticed the wires are steel core, 7mm, Prestolite brand. I was wondering if a carbon core type wire would work better or am I about to cause a problem? What will I get from a boat dealer? I can get an 8mm carbon core coil wire for about 1/2 the price of what I've seen in the parts site here. I am a first timer on the site. I have read information from this site before and have gotten lots of good info. Thanks in advance for any help.

 

[Joe Reeves]

Re: coil wires

Stick with the steel core s/plug wire(s). Carbon core will create problems. Check your present plug wires for continuity and correct as needed.

 

[OBJ]

Re: coil wires

tight-line...listen to Joe's advice. The carbon core wires have to much resistance and will cut down on your end spark.....the spark at the spark plug end.

 

[Scott Sutphen]

Re: coil wires

Thanks for the answers. Looks like I'll be getting 4 new coil wires. I did check the resistance on all the coils and they were all the same. The hour meter in the dash shows 960hr. Considering that this is a 1985 model engine, is that excessive hours? Thanks again guys.

 

[Hooty]

Re: coil wires

Excessive hours? That thang's barely broke in! <br />Seriously, if you haven't already, I'd put a compression gauge on it just for giggles. Get back and tell us what ya found.<br /><br />As far as ignition wires, I use Accel automotive high performance solid core wires (they come in colors) and they work great. NAPA may not stock 'em but they can get 'em.<br /><br />c/6<br />Hooty

 

[Scott Sutphen]

Re: coil wires

Got new wires from my local boat dealer. It was just easier and they had lots in stock. I did a compression check and had all cylinders read 125-130psi. Very little difference between any cylinder. I guess thats pretty good for compression. Also serviced the lower unit,fluid was pretty clear and not milky. Weather looks good this week. Time for the lake.

 

[seahorse5]

Re: coil wires

A tip for you. Remove each coil and sand the block and the coil grounding strap so that both are shiney. Corrosion can build up under the coils and cause intermittent misfires at various speeds due to aa bad ground.

 

[Scott Sutphen]

Re: coil wires

Thanks for the tip. I'm already hooked on this site. The information and sharing of knowledge is a tremendous help.