1972 Evinrude 65 - Replaced coils...now other troubles

cstute

Cadet
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Jul 2, 2009
Messages
6
I recently replaced the top two coils (the bottom one had previously been replaced) and now when I try to run with the cover on it acts like its only running two cylinders. When I take the cover off it runs great. I'm assuming its an exhaust problem but I don't remember messing with anything that I would have thought to be exhaust related. Any ideas of what I should look for?
 
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cstute

Cadet
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Jul 2, 2009
Messages
6
Re: 1972 Evinrude 65 - Replaced coils...now other troubles

Nothing on this one? Its got to be something simple...
 

EN2

Chief Petty Officer
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Nov 19, 2007
Messages
404
Re: 1972 Evinrude 65 - Replaced coils...now other troubles

If the motor runs good with the cover off,you are getting fresh air to the engine. Exhaust leakage from the power head to the mid section adapter is the cause. Also check to make sure one of the spark plug wires are not contacting the inside of the cover latches.
 

cstute

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Jul 2, 2009
Messages
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Re: 1972 Evinrude 65 - Replaced coils...now other troubles

Is there an easy way to see where the leak is coming from or what needs to be replaced. I don't understand how this exhaust leak could have started by just replacing the top coils?

Thanks in advance!
 

R.Johnson

Rear Admiral
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Sep 24, 2003
Messages
4,446
Re: 1972 Evinrude 65 - Replaced coils...now other troubles

As EN2 said, check that bottom cover latch that it's not snagging the bottom plug wire.
 

cstute

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Jul 2, 2009
Messages
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Re: 1972 Evinrude 65 - Replaced coils...now other troubles

So the wire cannot even be touching the bottom latch? I don't see how that could be doing it since thats the only coil that was not replaced.
 

TJShag13

Seaman Apprentice
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Jan 23, 2006
Messages
40
Re: 1972 Evinrude 65 - Replaced coils...now other troubles

Try running it at night and move the wires around to make sure that the spark isn't arching. I just replaced all 3 coils on my '72 johnson and I had to wrap the spark plug boot where the wires went into it because the spark was actually jumping from that point and arching out to the block.
 

R.Johnson

Rear Admiral
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Sep 24, 2003
Messages
4,446
Re: 1972 Evinrude 65 - Replaced coils...now other troubles

With a jumper wire grounded to the block, put the other end to a screwdriver. With the engine running probe across the plug wire's. I once had an engine with after market sparkplug boot's. I could touch the boot, and ground with a screwdriver, and short that wire out. You can't alway's take thing's for granted. That coil, and boot was new out of the box by the way.
 
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