1980 85HP Johnson

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BullFrog71

Recruit
Joined
Aug 28, 2011
Messages
3
When it runs good, it runs really good. Going down the lake at 4ooo rpm, like you flip a switch, it will drop to 2800 rpm with considerable power loss, may run all day like that , or may run a few minutes like that, then, like flipping a switch, back to full power and 4000 rpms. I think its a Spark Leaking problem, not sure. Fogged all the wiring with silicon spray lube, that seemed to help. It all seemed to start when I changed the spark plugs. ?????
 
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BullFrog71

Recruit
Joined
Aug 28, 2011
Messages
3
Re: 1980 85HP Johnson

Now no spark to coil on #1 , last time I checked, (last week), it was #3 that had no fire. it seems to change between #1 and #3 , first one has no fire then the other has no fire, never at the same time tho. Every so often, it will pick up that cylinder that hasnt been firing and it runs great, until the problem re-occurs, then back to either #1 or #3 not firing. I was told there could be a bad connection in the control box (where the key switch is) that would kill spark to one side of the engine. If that where the case, wouldnt it lose fire to both cylinders on that side ? I,m leaning more towards the trigger, (or whatever you call it) under the flywheel.........
 
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Sixmark

Master Chief Petty Officer
Joined
Jul 11, 2010
Messages
890
Re: 1980 85HP Johnson

Try swapping the power packs around from one cylinder bank to the other and see if the problem goes to #2 and #4
 
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emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: 1980 85HP Johnson

Follow sixmark's advice. That engine has two identical power packs, one for each head. Swapping them is a good test. If that does not change anything, test/qualify the stator and the timer base. You may find the ignition test procedures at cdi.com helpful.
 
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