Do I need new spark plugs???

[starkyb]

Yesterday I pulled the spark plugs on my 1988 75 horse Mariner. They were a little oily on the tops and on the threads. They are gapless plugs and are at least 3 years old or more. Is it time for a change and what difference will I see in performance. The motor runs pretty good but doesn't start up as fast as I would like especially if it is already warm.

 

[tjf]

Re: Do I need new spark plugs???

The motor is getting tired you can put new plugs in but you will have the same result soon after replacing the plugs..

 

[Mi duckdown]

Re: Do I need new spark plugs???

None.gapless hardly ever go bad. Good plugs

 

[starkyb]

Re: Do I need new spark plugs???

If there is a little oil on the plugs am I running a little too rich?

 

[Mi duckdown]

Re: Do I need new spark plugs???

Richer is better than leaner.

 

[starkyb]

Re: Do I need new spark plugs???

Does high octane gas help improve performance?

 

[Mi duckdown]

Re: Do I need new spark plugs???

NO.

 

[roscoe]

Re: Do I need new spark plugs???

High octane can actually hurt performance in a 2 stroke due to the burn rate and extra additives

regular old 87 or 89 octane is just fine.

 

[jerryjerry05]

Re: Do I need new spark plugs???

Just hit them with a wire brush.Gapless plugs should last as long as you want.I used a set for probably 10 years.They were still working good when I replaced them.
If your not performing as good as U used to.Do a compression test.Then start with the fuel system.Replacing the old hoses.The pump rebuild it.Get the carbs cleaned and reset.Ethanol is not our friend.J

 

[j_martin]

Re: Do I need new spark plugs???

Just hit them with a wire brush.Gapless plugs should last as long as you want.I used a set for probably 10 years.They were still working good when I replaced them.
If your not performing as good as U used to.Do a compression test.Then start with the fuel system.Replacing the old hoses.The pump rebuild it.Get the carbs cleaned and reset.Ethanol is not our friend.J

I disagree. "gapless" plugs, are really face firing plugs. The insulated electrode is cone shaped just like a regular plug. It's just less likely to foul, but it eventually gets dirty and can fail, and the electrode also eventually wears, increasing the gap.

They're only a coupla bucks apiece. Change them periodically (Spring tune-up for me) for preventativ maintenance.

 

[Silvertip]

Re: Do I need new spark plugs???

The technical term for those plugs is "surface gap".

 

[Kuna Matata]

Re: Do I need new spark plugs???

I am on this train as well. How often do you need to change them in a merc 3.0 L