Weird arcing at the plugs?

[Christobol]

I've got a 35 hp evinrude, 1976. When I turn the engine over holding the sparkplugs against the block, there is no spark between the electrodes, but when I hold it out from the block about a 1/2 inch it sparks from the threads and jumps over to the block.

I'm getting gas to the cylinders. It's blowing out the holes, but will not fire when I reinsert the plugs. Any ideas?

 

[F_R]

Re: Weird arcing at the plugs?

I've got a 35 hp evinrude, 1976. When I turn the engine over holding the sparkplugs against the block, there is no spark between the electrodes, but when I hold it out from the block about a 1/2 inch it sparks from the threads and jumps over to the block.

I'm getting gas to the cylinders. It's blowing out the holes, but will not fire when I reinsert the plugs. Any ideas?

Not so weird, they are shorted internally. Maybe cracked insulators, or just contaminated with conductive deposits. No matter, just replace the durn things.

 

[Rick.]

Re: Weird arcing at the plugs?

Beyond the plugs, look at the top of this forum at the Top Secret File for other possible causes. I agree with the new plugs though. Rick.

 

[Christobol]

Re: Weird arcing at the plugs?

Thanks for your help. I'll change out the plugs and see what happens.

 

[Christobol]

Re: Weird arcing at the plugs?

Update: I think I had corrosion on plugs. Replaced them. Starts, was running rough, added 3 oz of Seafoam to 1 gal of gas and ran for 25 min.- Cleared up the rough running, seems fine now. Thanks for your help!