1984 Johnson 50hp ignition spark jump

[jpbramlett]

I have a 1984 50HP Johnson. When the motor is running, one of the wires coming from the power pack to the coils is "spark jumping" to the engine block when I open up the throttle and increase engine RPM. I can't identify exactly where its happening at; it may also be coming from one of the coils and plug wire. <br />Whenever it happens it causes the motor to stall. It almost seems like the spark that is suppose to go to the plug never makes it - Instead it arcs over to the engine block. Is anyone familiar with this problem and have any reccomendations to fix it? Thanks in advance. <br />JP Bramlett

 

[Joe Reeves]

Re: 1984 Johnson 50hp ignition spark jump

JP.... Rig up a spark tester so that you will have a gap setting for each plug wire. Set the gaps to 7/16". Remove the spark plugs of course.<br /><br />Turn the key to the ON position. Crank the engine by using a small jumper between the battery side of the starter solenoid to the energizing 3/8" nut on that solenoid (not the 3/8" ground terminal). While cranking and observing the spark, move the throttle through its full range. That should reveal the problem area, and if so, the cure should be obvious.

 

[jpbramlett]

Re: 1984 Johnson 50hp ignition spark jump

Mr. Reeves,<br />I'm pretty sure the arc is occuring in the wiring or plug connecting the powerpack and coil. I was right on top of the motor yesterday and could hear the arc and feel it in the impeller stream. Is it possible, or normal, for it to arc through insulated wiring to the engine block - or do you think I have exposed wire somewhere? I will check to see if I'm losing spark at the end of the plug wire when the arcing occurs. It seems to be because of the motor stalling. <br />By the way, where are you from in central Fla? I grew up just N. of Tampa. <br />Thanks again.