Should spark plugs be changed every year?

Cudos

Seaman
Joined
May 20, 2010
Messages
69
I've got a 86 ER 120 looper. Should the plugs be changed yearly? I also fogged the motor and the cyl's before putting to bed. I have her running, seems ok. Will the plugs dry themselves off eventually?

Thanks
 

HighTrim

Supreme Mariner
Joined
Jun 21, 2007
Messages
10,486
Re: Should spark plugs be changed every year?

You will likely get a wide variety of answers here.

Do I change my plugs every year? Yes I do. But I am pretty anal about my maintainance. It is likely based more on the hours used rather than a time duration. Also, plugs are very cheap. We are not talking about a high ticket item here.

On the other hand, will you do any harm in simply cleaning them and re gapping? Probably not.

Sorry for the double answer, but it is more of a personal choice. If you do prefer cleaning and re gapping, at least keep an extra set on board just in case.
 

Auxlarry

Petty Officer 1st Class
Joined
May 21, 2010
Messages
304
Re: Should spark plugs be changed every year?

I agree with HighTrim on this issue. I change mine about twice a year but this because I put a lot of hours on them, but I clean and gap them quite often also.
 

kenmyfam

Supreme Mariner
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Aug 10, 2006
Messages
14,385
Re: Should spark plugs be changed every year?

Agree with the amount of use mentioned above. Used to change mine every year but as I have used less over the last few years I am changing every 2 years and keeping the previous good and still working ones on board as spares.
My 2 cents on the subject.
 

wifisher

Chief Petty Officer
Joined
Mar 9, 2011
Messages
578
Re: Should spark plugs be changed every year?

I check them every year (mostly). I don't change them unless they look bad, or start causing trouble. Spark plugs are probably the most over-replaced part in the world.
 

steveb101

Cadet
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May 23, 2011
Messages
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Re: Should spark plugs be changed every year?

If still in doubt, refer back to Hightrim.
 

samo_ott

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Re: Should spark plugs be changed every year?

I'm on the no side. I never change my plugs unless there's a problem. As long as it's running well I leave em. Then if they're in question I clean and re-gap and and still use em. Every so often I find an intermittant plug. Just changed one last week on my 70's Johnson 25hp. Couldn't figure out why it was running on one cylinder every so often (new ignition system) and changed the plug and voila...
 

HighTrim

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10,486
Re: Should spark plugs be changed every year?

I'm on the no side. I never change my plugs unless there's a problem. As long as it's running well I leave em. Then if they're in question I clean and re-gap and and still use em. Every so often I find an intermittant plug. Just changed one last week on my 70's Johnson 25hp. Couldn't figure out why it was running on one cylinder every so often (new ignition system) and changed the plug and voila...

Yeah but Steve MOST people do not have 150 outboards to change plugs in every year. You would need to remortgage to do that. :)
 

samo_ott

Vice Admiral
Joined
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Messages
5,125
Re: Should spark plugs be changed every year?

Hey, I only have around 70! But run less than 10 per year... And I just got a 90hp 6 cylinder Merc on my 24' pontoon boat... Yes 6 friggin cylinders! That's alotta plugs to change!! I wanna sell it as soon as I can and put a good ole OMC on the boat!
 

jimmacl

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Joined
May 8, 2011
Messages
25
Re: Should spark plugs be changed every year?

I only have 10 working motors.:( I change my plugs on my main motor once a year, the rest I always seem to have a "good" set of 6j6s around. A bad plug can take out coil/points, I think it may have happened once to me.

jim
 

samo_ott

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Re: Should spark plugs be changed every year?

I have not heard that a bad plug can take out a coil. How does that happen?
 

jbjennings

Captain
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Jul 18, 2007
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3,903
Re: Should spark plugs be changed every year?

I change mine out on my main motor about once every 4 or 5 years, or when the electrode is worn down so much it can't be regapped properly-------whichever comes first. :) I take great pride in a well-worn spark plug electrode. It shows I've been doing what men were put here on earth for.......BOATING!!!
But I do try to bring a spare.
I also had to change them out a lot more often on the early 80's 15hp johnsons I ran. They liked new spark plugs.
I've got several motors from the 50's that are still running great on spark plugs from the 50s as well.
JBJ
 

apollothesun

Petty Officer 3rd Class
Joined
Nov 3, 2010
Messages
79
Re: Should spark plugs be changed every year?

sorry to reserrect this topic but whats the best way to clean your spark plugs?
 

atlapp

Seaman
Joined
Sep 25, 2010
Messages
51
Re: Should spark plugs be changed every year?

do not replace unless plug shows evidence of wear...i have some plugs in my engine that are 4 or 5 years old....I do however always have extra plugs!
 

ohioriverat

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Aug 7, 2011
Messages
115
Re: Should spark plugs be changed every year?

Plugs are the first thing i change,to me it's cheap insurance..
 

F_R

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Jul 7, 2006
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28,195
Re: Should spark plugs be changed every year?

If they need to be changed every year, I'm in a heap of trouble. I've only changed the ones in my 1984 Johnson once---and they didn't need it that time.

But of course, a whole lot depends on what motor we are talking about. Some go through plugs extremely often. And as a general rule, modern engines with a good CD ignition system do not burn the electrodes off like the old magneto and/or battery ignition systems did.

So, the answer is "it depends".
 

robert graham

Admiral
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Apr 16, 2009
Messages
6,908
Re: Should spark plugs be changed every year?

sorry to reserrect this topic but whats the best way to clean your spark plugs?
I bought a Harbor Freight Spark Plug Sandblaster($15) about 10 years ago, never buy new plugs for outboard, chainsaws, blowers, etc. Sandblaster knocks carbon off plug center electrode insulator and other areas. Plugs don't much wear out, just get fouled. :) Sandblaster has paid for itself repeatedly, but you need an air compressor to operate it. Water cooled 2 stroke outboards seem to make carbon/deposits more than air cooled chainsaws and blowers, maybe high temperatures of air cooled motors burns off deposits? Good Luck!
 

rico suave

Seaman
Joined
Jul 18, 2008
Messages
52
Re: Should spark plugs be changed every year?

If everything else is OK, fuel, carburetor, spark, and points set properly, then the answer is no. Most people have some issue starting their motor at the start of every season and their first gut reaction is to replace the plugs when in actuality the real problem is one of those other things mentioned above. I have to admit though I have done the same, replaced plugs first, and then found the real problem (usually fuel/carb) later.
 

OptsyEagle

Lieutenant
Joined
Sep 13, 2006
Messages
1,356
Re: Should spark plugs be changed every year?

I kind of look at the plugs and if they look like the combustion has been working well, I re-gap them and re-use them. After 3 years, I change them completely.

I use my motors quite a bit, but since I have three, this method is a lot like changing them every year with only one motor. In any event, if the motor is firing well and the fuel is combusting properly, I don't think they need to be changed every year.
 

V153

Lieutenant Commander
Joined
Apr 16, 2011
Messages
1,764
Re: Should spark plugs be changed every year?

I tend to agree with the if it ain't broke don't fix it school of thought. But I don't mean just set em & forget em either. If you boat a lot it pays to inspect plug condition & check gap every few months. A spark plug can tell you a lot about how your motor's running.

Fwiw I've been running NGK Irridiums in my 90 crossflow for over 4 yrs now. Lil pricey perhaps and some might say overkill. But I believe the benefits & longevity offset the initial cost. Have no hard evidence to support it but seat of the pants tells me the motor does run better. In particular it's noticably smoother through idle speed no wake zones. No more of that occasional sputter or wheeze?

Ya those little plug sandblasters work great! Just don't use too course sand or you'll actually open up pores for the carbon to adhere to. Or so I'm told ...
 
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