85 115 johnson

[harve]

Was towing ski for about an hour when engine quit. Starter cranks but no spark. I read in another posing that it may be the rectifier, being new to boating I have no clue what that is, where to find it or how to test it, anybody want to give a novice the walk through? Also the 4 rounded grey things (good description eh) that have the spark plug wire come out of prior to the plugs on one side have some small cracks in the plastic coating should these be replaced? Thanks

 

[Joe Reeves]

Re: 85 115 johnson

Harve.... The rectifier converts AC from the stator to DC which is needed to charge the battery. If you have a tachometer and it works, the rectifier and the charging system are okay. The rectifier has nothing to do with supplying power to the powerpack, coils, or ignition in general.<br /><br />Those round gray things are ignition coils.<br /><br />Rig up some kind of spark tester whereas you can set a 7/16" gap.<br /><br />Find the large RED electrical connector at the engine and disconnect it. Remove the s/plugs. Crank the engine by using a small jumper from the battery cable side of the starter solenoid to the small 3/8" nut terminal that energizes the splenoid (not the 3/8" ground terminal).<br /><br />If you now have spark, in all probability the ignition switch has shorted out. If so, replace it. If you still do not have spark, the usual failure is the powerpack.

 

[harve]

Re: 85 115 johnson

Thanks for the advice Joe. No spark so I guess I'll try replacing the ignition switch, would the starter motor still crank the engine if the starter switch had shorted out? thanks Harve