85 HP Evinrude. No spark on #3 cylinder

crstrode

Cadet
Joined
Jul 2, 2003
Messages
8
Just bought a 1977 85 HP Evinrude as part of a package deal.<br /><br />Before trying to run it I bought a new gas tank, new gas line and primer bulb. New gas and fresh mix.<br /><br />First try on the lake it started up OK, and seemed to run fine, although with a bit of vibration.<br /><br />After running for about 15 minutes, the power began to surge, the vibration stopped and we were going faster ( for only a few seconds at a time).<br /><br />Back at the dock, #3 cyliner seemed to be cooler to the touch than the others. Pulling the plug wire from #3 cylinder had zero effect on the motor.<br /><br />Swapped the plug from #1 to #3 and no change. The #1 cylinder worked great on the plug from #3.<br /><br />Pulling the #3 plug and running the motor I could not see any spark at the plug with it grounded out to the block.<br /><br />Please, give me some troubleshooting tips. <br /><br />Thanks,<br />Carl<br />Cheney, WA<br /><br />PS: I hope I can get this motor fixed, because with only 3 jugs hitting, my 27 foot pontoon barge is kinda pokey!
 

Solittle

Fleet Admiral
Joined
Apr 28, 2002
Messages
7,518
Re: 85 HP Evinrude. No spark on #3 cylinder

Carl - Welcome to the place to get more info on boats & motors than any other. - - - Some of the asvice is actually pretty good.<br /><br />Just as you swapped the #3 plug do the same with a plug wire on #3. If no change repeat the process with a coil.
 

crstrode

Cadet
Joined
Jul 2, 2003
Messages
8
Re: 85 HP Evinrude. No spark on #3 cylinder

After reading about a zillion posts, it seems that the coil & plug wire, the powerpack, and the #3 sensor are the three most likely culprits.<br /><br />The boat and motor are a long way away and not near any repair shops or parts supply.<br /><br />I've taken off the coil and brought it back to town.<br /><br />Using my multimeter, I measured the resistance of the coil.<br /><br />Between the wire that goes to the power pack and the ground wire I measure about 0.15 ohms.<br /><br />Between the plug wire connector and either of the other wires is open (infinite resistance).<br /><br />From any of the three wires to the metal core mounting is also open.<br /><br />Is this correct? I was expecting to find some indication from the plug wire connector to one of the other wires.
 
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