'78 Evinrude 140 no spark starboard side while cranking

[MaPaHa]

My '78 140 V-4 crossflow motor runs ok but it does have a little trouble at low speed. It takes off fine and runs out good. I bought a spark tester to use on another motor and got no spark at all so I wanted to test the tester. I put it on both plug wires on the starbord side of this motor and got absolutly nothing during cranking the motor over. The port side was good at 1/2 inch spark or so.

Surly this motor is not designed to start on two cylinders is it? If not, any input? I have not tried it while it's running.

 

[Joe Reeves]

Re: '78 Evinrude 140 no spark starboard side while cranking

The spark test must be performed with "ALL" of the spark plugs removed in order to obtain the highest cranking speed available. The engine must turn over at least 300 rpms in order to fire all four (4) s/plugs.

In cranking to start, normally one plug or another will fire that of course increases the rpms instantly which causes the other plugs to fire. Yes, I know a lot of fellows won't believe that statement, however it is the case.

 

[emdsapmgr]

Re: '78 Evinrude 140 no spark starboard side while cranking

Follow Joe's procedure first. That engine uses two identical power packs. One pack for the two coils on each head. They can be swapped for testing purposes. See what happens after you swap the packs.

 

[MaPaHa]

Re: '78 Evinrude 140 no spark starboard side while cranking

Ok thanks,
The motor starts and runs too good for one side to be dead so I wondered if I was missing something. I'll do a test with all of them out and see what happens, but wouldnt be supprized if that side came up weak.