Proper Spark Plug Appearance

[jtexas]

A number of posts have indicated that there should be some oil on the spark plugs - just to be sure, is that on the electrodes & insulator? The manual says they should be "dry and powdery" which mine are, but I do have some oil accumulating on the outside of the shell, on the threads.<br /><br />thanks,<br />jtw

 

[roscoe]

Re: Proper Spark Plug Appearance

Depends on the engine.<br />A 4 stroke may have dry, light tan plugs.<br />But I don't think you want dry plugs in a 2 stroke. I always have damp to wet plugs in my 2 strokes.

 

[Cricket Too]

Re: Proper Spark Plug Appearance

Yeah if you have dry and powdery plugs on a 2 stroke you are running way to lean and probably done some damage.

 

[chris abela]

Re: Proper Spark Plug Appearance

you must be talking about a 4 stroke, 2 stoke are always oily

 

[jtexas]

Re: Proper Spark Plug Appearance

This is a quandry. It's a 3-cyl 2-stroke 1979 70hp evinrude. Seloc manual says plugs should be dry. Does it make a difference whether the engine is warm or cold when I pull 'em? (it was cold) Does running too lean = over-temp? What kind of damage? Motor runs like brand new.<br /><br />thanks,<br />jtw

 

[chris abela]

Re: Proper Spark Plug Appearance

the issue here is if the engine is geting enough oil to lubricate with. Dry plugs would indicate a dry unlubricated engine interior.

 

[Cricket Too]

Re: Proper Spark Plug Appearance

What is the condition of your carbs? How long has it been since they were rebuilt and has this engine been sitting for a while? Are you running a 50:1 premix? Yes running lean does = running hot and can damagage pistons, cylinder walls and basically all internal parts. Those plugs should have some oil on them at least, especially if you idle for a while before shutting it off, like docking.

 

[jtexas]

Re: Proper Spark Plug Appearance

Carb rebuild was done last October by a reputable mechanic, plugs replaced at that time with NGK, had it out at least every 3 weeks or so since. I premix at 50:1 & I'm pretty confident about that. I checked the plugs about a day and a half after the last use, which did finish up with idling to the dock & trailering. Didn't warm it up before checking the plugs. The threads were oily but inside they are dry. All three looked exactly the same - dry & brownish. Had it out once since then, still runs great.<br /><br />I appreciate your help,<br />jtw

 

[G DANE]

Re: Proper Spark Plug Appearance

On my 25 HP: If you pull plugs after warming motor up up iddling, plugs are wet, blackish and oily. If you pull them after running wot for some time, returning to dock by iddling one or 2 min, they are mid to dark brown, like coffee with a little cream in. It always was like that, and im sure it is fine. If you start it and let it warm up in iddle and have dry plugs, it could sound like your on the edge with lean mixture, or below 1:50 oil/gas.

 

[walleyehed]

Re: Proper Spark Plug Appearance

Make lure retrievers out of those NGK's and put the proper Champions in.......

 

[jtexas]

Re: Proper Spark Plug Appearance

I really appreciate having the benefit of all y'all's experience.<br /><br />I have to keep the boat at a storage yard w/no water or electricity and we got a serious cold snap here (about 25 degrees this morning) so it might be a few days before the temp gets back up to tolerable on a weekend so I can get back to it, but when that happens I'll put in champs & check 'em after idling a bit & let you know how it comes out.<br /><br />Didn't know I had NGK's until just now but I guess I can keep 'em around as spares.<br /><br />thanks again,<br />jtw

 

[lund17]

Re: Proper Spark Plug Appearance

A cold snap all y'all is about -10. What y'all got there at 25 is a warming trend. LOL