Spark plug on your outboard-do you ever change it?

[ffiill]

Whilst you may adjust the spark plug on your outboard how often do you change it?
I ask because I just realised that the one in my Seagull will be fifty in 2017!
Actually I intend to replace it shortly.
I have always carried a modern spare but it has just kept going.

 

[Spyro]

Once in ten years because I was having some starting trouble. It wasn't the plug. It was a gummed up carb.

 

[Skylark]

Once in ten years because I was having some starting trouble. It wasn't the plug. It was a gummed up carb.

Interesting. Last season I changed the plug in my 10 year od Tohatsu 2.5 hp. I, too, was having starting trouble which was resolved with a new plug.

 

[VicS]

Changed the plug once only AFAIR in my '74 Featherweight because it was not running well and once more because I broke the terminal off ( but that one is glued back together and is now in the lawnmower)

Not tried modern replacements as I still have a couple of new 8COMs

Not keen on stale fuel but I do normally find last years 50:1 mix, with extra oil added, OK

Got two sets for the '84 Evinrude. Original pair and a spare pair of similar age. Could not at any one time tell you which is in service.

 

[Avocet]

I worry that as a plug ages, the voltage needed to fire it will go up and put the coil under greater strain so that there's more change of wrecking it (and other ignition system components)?

 

[lw395]

I worry that as a plug ages, the voltage needed to fire it will go up and put the coil under greater strain so that there's more change of wrecking it (and other ignition system components)?

More likely it becomes contaminated and does not spark properly?
Unless the gap has got huge.
I like to have a spare, would change it as a diagnostic measure, or if the old one was visibly horrid.
Very few people do enough hours with outboards to wear a plug out, but over oiling and bad fuel seem to take their toll.