Melting spark plug Honda 90

firstlight

Cadet
Joined
Jul 26, 2005
Messages
24
I talked to an automotive mechanic about the spark plug problem in my previous post (spark plug story). He feels that the #2 cylinder is running extremely hot and softening the side electrode enough to bend. The engine compression is closing the gap. It's his opinion that the carburetor on that cylinder is running rich, thus hot. I've never changed the adjustments and am shy about doing it now.....any advice??
 

gss036

Commander
Joined
Jan 18, 2003
Messages
2,914
Re: Melting spark plug Honda 90

I am not a Honda mech, but I would think that rich carb would run cold. I would be thinking too lean! At any rate carb rebuild time to make sure you get it right.
 

javsam

Chief Petty Officer
Joined
Aug 24, 2005
Messages
421
Re: Melting spark plug Honda 90

have you changed any ignition parts?sometimes the timing changes when ignition parts are changed..I would also have the timing checked then I would check for a lean condition.<br />javsam
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: Melting spark plug Honda 90

I dont follow this forum much. your question is interesting.<br /> YOU HAVE BAD things going on inside the combustion chamber.<br /> ask your auto mechanic friend about the effects of lean air/fuel ratioas at or near wide open throttle.<br /> my guess is his peepers will glze.<br /> most auto techs never hear of an issue at 4700 RPM after 20 minutes.<br /><br /> if your wiping electrodes first thing is to do a leakdown test to inspect for any mechancal damage. if none is found go find why the combustion temps are spiking.<br /> usually a crossfire or a lean carb mixture.<br /> GSSo36 is correct. a rich mix will actually cool combustion temps but can be terrible on exhaust temps.<br /> doesnt matter if your a honda,mitsubishi,chevy or yamaha tech. they all have to work with very narrow paremeters.<br />suck,squeeze,bang and blow. everything else just helps it go.
 

clarkperez2334

Recruit
Joined
Aug 23, 2010
Messages
1
Re: Melting spark plug Honda 90

Well, spark plug is so exposed to high-voltage electricity that's why it easily gets damaged like melting. And for me, i'll just replaced it with a brand that would really last :)
 

hondon

Lieutenant Commander
Joined
Jun 11, 2001
Messages
1,922
Re: Melting spark plug Honda 90

It is not inconcievable that you have some water intrusion happening into that cylinder.A boreascope would be the tool of choice here too see if the top of that piston is washed out.
 

gss036

Commander
Joined
Jan 18, 2003
Messages
2,914
Re: Melting spark plug Honda 90

The last post is spam and totally inappropriate for this forum, it need to be removed.
 
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