Weak or intermittent spark on one bank, Power Pack Test '74, 115 hp Evinrude

[harrylarson]

This concerns a post I had started previously, my 74, 115 hp, Evinrude barely runs after idling for about 15 minutes. Put inductive timing light on wire for each cylinder, 1 & 3 seem fine, steady strobing light. 2 & 4, the other bank, the light seems intermittent and weak. Could someone please confirm what I understand to be a test of my Power Pack? Switch orange ignition coil wires at Power Pack for cylinder 1 & 3 with ignition coil wires for 2 & 4, respectively, if problem jumps to the other bank then the Pack is bad. Yes? Also is it OK to start motor with the wires swapped? Because I don't know if I can check the inductive light when just turning with the starter.

 

[Faztbullet]

Re: Weak or intermittent spark on one bank, Power Pack Test '74, 115 hp Evinrude

A weak stator can also cause this due to bad charge coil. Swap the brw/yell and brn wire postions and see if problem follows, if so replace stator.

 

[emdsapmgr]

Re: Weak or intermittent spark on one bank, Power Pack Test '74, 115 hp Evinrude

You may find some good electrical troubleshooting tips on the cdi website: cdielectronics.com.

 

[harrylarson]

Re: Weak or intermittent spark on one bank, Power Pack Test '74, 115 hp Evinrude

I swapped the orange coil wires at the power pack for cylinders 1 & 3 with the ones for 2 & 4. The problem did not jump to the other bank but stayed on 2 & 4, sometimes there was no spark at all on this bank. Can I assume it's not the power pack since the problem did not jump? Any suggestions?

 

[RDJuhl]

Re: Weak or intermittent spark on one bank, Power Pack Test '74, 115 hp Evinrude

I have a 1973 85 HP Evinrude which had similar intermittent spark issues. Following the wise advice of other members, I took a couple hours and cleaned every electrical connection I could find which was related to ignition...key switch, coils, power pack, spark plug wires, grounding straps, etc. (Pay extremely close attention to all ground straps and wires).The spark plug connections inside the boots had significant corrosion on a couple of the wires, so I replaced those. The engine then fired up very quickly. I used sandpaper, as well as a dremel with a stainless steel wire brush.

Let us know if you find the problem.