75' 40 horse spark jumps across ceramic on spark plug

A

abfrench

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Model 40555c 1975 40 hp rude, I am at wits end need assistance. I installed 2 new ig. coils factory parts, high tension wires, proper plugs with proper gap(checked with feeler gauge) All wires are isolated and insolated. I am in the middle of a banner walleye season. My motor has two probs. Bogging at high Idle, (surely a clogged jet or cracked fuel line). More intriuging I fish at night and pulled the hood off only to see lightning bolts crossing the porcelin. The motor IS variable with its symptoms. This is not a high performance machine I just want something for my kids to be able to spank big sloppy eye's
 
fireman57

fireman57

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Re: 75' 40 horse spark jumps across ceramic on spark plug

You may have cracked the ceramic on the plug when you put it in our you have a bad plug wire. When you put the new coils in I bet they were the ones that you have to assemble yourself. They are kinda of tough to get right. Put a new plug in that one first and see if it helps, make sure that you have the coil plug end snapped onto the plug.
 
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abfrench

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Re: 75' 40 horse spark jumps across ceramic on spark plug

thanks for reply fireman57, arcing occurs across <br />both plugs regardless of which plugs i use, both boots are brand new. plug wires terminate into little spring dings that you poke through the plug wire then jam into the boot. I can hear the spring slide over plug end, on both plugs, let me also offer that this seems to happen after the first 5 mins of operation, just after hitting high Idle, Problem then occurs at all rpm after initial failure, I will re-do the plug end assemblys just to rule that out, but I am sceptical, thanks again, any other thoughts?
 
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abfrench

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Re: 75' 40 horse spark jumps across ceramic on spark plug

I installed this motor myself is there any way I failed to do something very basic? I.E is there an issue with grounding?
 
fireman57

fireman57

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Re: 75' 40 horse spark jumps across ceramic on spark plug

Make sure that all your ground connections on this engine are clean. Didn't realize that it happened on both plugs. Never seen that. There will be an expert along in a minute that will know more.
 
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