piston problem, 98' 90hp evenrude

dansoph

Petty Officer 3rd Class
Joined
Oct 30, 2002
Messages
86
the electrode on one spark plug is mashed over.any idea why? thanks for any help dan
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: piston problem, 98' 90hp evenrude

if your motor is a ficht, disregard this.

you should be using Champion plugs, 90* motor QL77JC4 or QL82C 60* QL78YC, people love to put other brands in these motors.

you need to take a flash light and check if the piston is damaged.
 

dansoph

Petty Officer 3rd Class
Joined
Oct 30, 2002
Messages
86
Re: piston problem, 98' 90hp evenrude

thanks for your reply. i hope this isn't a dumb question, but how could the electrode get damaged? thanks dan
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,930
Re: piston problem, 98' 90hp evenrude

I would pull the head and inspect the cylinder. This engine uses o-rings so dont worry about the a head gasket. If electrode is mashed something came thru cylinder to get on top of piston. It could have been a nut,screw or piece of piston skirt. Any strange noises before it happened or loss of power?
 
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