1970 Evinrude 6hp spark issues.

FZ1

Seaman Apprentice
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Sep 22, 2008
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33
Here's a new one to me, and I've been working with engines for a long time. I've done new coils/points/condensers/ on this motor and now it runs good (one one cylinder!) Upper cylinder doesn't fire, pulling the plug wire off when running does nothing. Not even any of the snapping you usually hear when you have the electrode near the plug. The weird thing is that I get almost a 1/2" blue spark jumping off the bare wire to ground when spark testing this wire. Its the top cylinder so its the one where the spark plug wire wraps almost all the way around the ignition plate and is almost 3 feet long, so I'm guessing its the wire shorting somewhere, though i'm damned if I can find it! New wires on their way tomorrow. Anyone else ever experience this?
 

Daviet

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Sep 24, 2008
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Re: 1970 Evinrude 6hp spark issues.

Just a thought, are you sure it's an ignition problem, what does the plug look like?
Doesn't your fuel pump mount to the upper cylinder?
I have seen the diaphram in the fuel pump leak and flood the upper cylinder and foul the plug.
Just something else to think about.
 

Rick.

Captain
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Jul 30, 2006
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3,740
Re: 1970 Evinrude 6hp spark issues.

Get someone to pull the recoil in the dark of night and have a close look for spark jumping to ground. Best of luck. Rick.
 

Tim Frank

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Jul 29, 2008
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5,346
Re: 1970 Evinrude 6hp spark issues.

You don't mention whether you changed the plugs. Might start there to rule out a plug problem.
 

FZ1

Seaman Apprentice
Joined
Sep 22, 2008
Messages
33
Re: 1970 Evinrude 6hp spark issues.

Great Idea Daviet... but no. It was a shorting plug wire somewhere. I've now got spark on both and I'm dealing with a dirty carb. It runs on both but wont idle and the low speed mixture has no real effect, so I'm going to tear it down again. I tried to not remove the welch plug above the low jet but i think i might have to.
Just a thought, are you sure it's an ignition problem, what does the plug look like?
Doesn't your fuel pump mount to the upper cylinder?
I have seen the diaphram in the fuel pump leak and flood the upper cylinder and foul the plug.
Just something else to think about.
 
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