200+ hour spark plug change

[FSH 210 Sport]

I ran these plugs last year for well over 200 hours, probably closer to 250 hours. The gap had increased by .002” from .028” to .030” and the electrode still has sharp corners. The insulator is the same color all the way to the base inside the plug. To be fair, the vast majority of those hours were at idle / fast idle while trolling. The engines still ran great and revved to max rpm.

 

[diehard]

you also use good gas

 

[FSH 210 Sport]

you also use good gas

This is true! I run non ethanol at 86 octane and use Amsoil top end lubricant religiously. There are times when I travel that I can only get 87 octane non ethanol and a couple times a year I will run a tank of ethanol laced 87 through the tank, usually when Non ethanol is not available, running the ethanol 87 will clean the fuel system up and pick up any water that is in the tank.

 

[CastawayRK]

The ground electrodes sure are clean. They are good to go another 200 hours but since they are out might as well replace them.

 

[biffdotorg]

I ran these plugs last year for well over 200 hours, probably closer to 250 hours. The gap had increased by .002” from .028” to .030” and the electrode still has sharp corners. The insulator is the same color all the way to the base inside the plug. To be fair, the vast majority of those hours were at idle / fast idle while trolling. The engines still ran great and revved to max rpm.

To be fair, was there a question in that statement? If it was should I run them? The answer is why change something that is that clean and working. You did your annual inspection, now let 'em buck. Pitter Patter, let's get at 'er.

 

[tdonoughue]

For the record, even as wonderful as these look, given how finicky our boats can be with plugs, I would still have changed them. Cheap insurance.

I take this as a testimony to good boat and engine care. Well done.

 

[FSH 210 Sport]

For the record, even as wonderful as these look, given how finicky our boats can be with plugs, I would still have changed them. Cheap insurance.

I take this as a testimony to good boat and engine care. Well done.

Thanks! I figured I’d just keep running them last year unless an issue came up and nothing came up!

 

[biffdotorg]

For the record, even as wonderful as these look, given how finicky our boats can be with plugs, I would still have changed them. Cheap insurance.

I take this as a testimony to good boat and engine care. Well done.

So many people say "cheap insurance" insurance against what? There are very few if any catastrophic breakdowns from spark plug failure unless it breaks. The worst case is usually lack of spark and dropped RPM's. And then you change them. Easy enough, no insurance needed. And can easily be done on water.

This saying makes more sense when talking about the drive belt on a snowmobile or sxs. If it fails, you are done and a spare is always needed. If one spark plug out of 8 fails, you still have a boating day to complete. Many don't even notice it, unless they are attentive to a miss or lowered RPM's when on plane.

 

[tdonoughue]

So many people say "cheap insurance" insurance against what? There are very few if any catastrophic breakdowns from spark plug failure unless it breaks. The worst case is usually lack of spark and dropped RPM's. And then you change them. Easy enough, no insurance needed. And can easily be done on water.

This saying makes more sense when talking about the drive belt on a snowmobile or sxs. If it fails, you are done and a spare is always needed. If one spark plug out of 8 fails, you still have a boating day to complete. Many don't even notice it, unless they are attentive to a miss or lowered RPM's when on plane.

You must be one of the fortunate few who has never been stuck out on the water with a boat that won't start (and no new plugs lying around) or has had plugs seized in the block. I'm not saying you need to change yours. You are free to do you. Me, I find it cheap insurance against a boat that won't start when I want it to or breaking a plug when it won't come out.

 

[TommyMcK]

You must be one of the fortunate few who has never been stuck out on the water with a boat that won't start (and no new plugs lying around) or has had plugs seized in the block. I'm not saying you need to change yours. You are free to do you. Me, I find it cheap insurance against a boat that won't start when I want it to or breaking a plug when it won't come out.

As for me, I treat plugs like underwear. Change 'em out every two years whether they need it or not. So you won't get an argument from me regarding frequency. I think that biffdotorg was saying that the failure of a single plug won't strand you, and that you'll likely notice a performance issue before anything big happens....which seems reasonable to me.

 

[Neutron]

If one spark plug fails, yes have a great chance of making it back to the dock. But if you have a long way back, say an hour, the injector is still spraying and can and most likely wash the rings and end up in the oil.
I will keep an old "great looking" set on the boat for that reason.

 

[biffdotorg]

As for me, I treat plugs like underwear. Change 'em out every two years whether they need it or not. So you won't get an argument from me regarding frequency. I think that biffdotorg was saying that the failure of a single plug won't strand you, and that you'll likely notice a performance issue before anything big happens....which seems reasonable to me.

100% the point. Inspection avoids the chance of seizure or surprises in a lean condition. I always have 8 new ones sitting in my shop for that every other year swap or when I hear a miss at speed (whichever comes first) Very few have ever been stranded due to one failed plug.

This would be a totally different story if I spent my hours running the intercoastal, or trips across open water like Bimini. Then they are considered insurance. But in my case where my boat sits on a lift on one lake, there is little risk of being stranded. Running out of beer is more likely. (smile)