1980 Evinrude 115 Spark plug Hit !!Is it worth investigating?

wingman99 · #1 July 24th, 2009, 06:54 PM

Hi
I was wondering.. if I need to start taking this engine apart to figure out what is causing the piston to be loose and hit the spark plug how much money could it be ??and I guess I am committed if I start??? Is it worth the work or should I look for another motor or boat and motor instead of fixing this old worn motor. I was told when I bought the boat that the motor was just re-built but it was a private sale. Should I go back to the seller???1980 Evinrude 115.....

Thanks

tashasdaddy · #2 July 24th, 2009, 07:28 PM

what spark plugs does it have in it?

AEROCOOK · #3 July 24th, 2009, 07:29 PM

A few questions...
Does the motor run? Is it just 1 plug that is hitting? Has it done this since you first bought it or did it start doing it after a few trips? Does the motor knock when it runs?

wingman99 · #4 July 24th, 2009, 10:41 PM

Hi there...
to answer questions ,,,Yes the plugs are correct I checked in my manual and at the marine shop on the phone. It was running for the 2 days I was camping but short on RPM part way through the first day. Still was running when I removed it from the water. I honestly did not hear any loud unusual sounds or nocking. Yes it is just one plug. It is a 2 stroke so it is pretty loud but not sure. It must have just happened because I had the plugs out before the weekend that I was going out and they didnt look like that. The only reason I was looking for problems was because of my drop in RPM from the first day and wondered why? Checked fuel lines first and then plugs and noticed this problem.
Thanks

kenmyfam · #5 July 24th, 2009, 11:03 PM

So what plugs do you have in there ???

wingman99 · #6 July 25th, 2009, 12:08 AM

The plugs are NGK I believe but I am not at home to look. The back up ones I had were Champions and I checked them for size against these and they looked the exact same. The champions were the same number as in my manual for 1980 115. I will look at home tomorrow if you need exact # on plug??

emdsapmgr · #7 July 25th, 2009, 07:25 AM

You may have suffered a ring failure on one piston that first day out. These crossflows can crack/throw rings with age and any loose ring debris can circulate in the combustion chamber (possibly hit the plug) before it gets chewed up and exits through the exhast system. I'd pull the plug, shine a light into the spark plug hole in question and see what it looks like. You may even want to pull the head on that side for a closer inspection, or pull the side bypass cover and see if anything is visible. Dents in the piston top and head face indicate a cracked/missing ring.

divinginn · #8 July 25th, 2009, 03:10 PM

I have seen a rod bearing gone bad do that before,it would hit the plug and close the gap.

AEROCOOK · #9 July 25th, 2009, 04:46 PM

Quote:

Originally Posted by divinginn

I have seen a rod bearing gone bad do that before,it would hit the plug and close the gap.

Ill bet it was making a lot of noise.