Should I really replace zincs/plugs?

[Yamama]

I did my annual maintenance this past weekend. The Yankee cheapo in me came out and I started wondering if I wasted $50 or so in replacing these items. Does anyone really know what makes a plug or zinc worthy of replacement, or is it that springtime knee-jerk reaction of better safe than sorry attitude?

Here's the items:

 

[Stonewall]

I would definitely replace the Zincs. They are a cheap alternative to expensive repairs. You can get them real cheap at the Zinc Doctor.
http://thezincdoctor.com/index.html

As for the spark plugs - not sure. You may be able to just clean them up and get another year. But again - they are notthat expensive. It will be one less thing to worry about when you are out on the water.

 

[Hookup1]

Zincs

At the dock the handle bar zinc on my engine is sometimes in the water. It tends to collect marine growth but doesn't erode. I clean the zinc up and re-use it.

The engine tab zinc is always out of the water at the dock. It gets some erosion from the prop wash but it isn't bad enough to replace.

The trim tab zincs always get eaten up.

 

[3rd Day]

Replace the plugs (they are cheap insurance) and tab zincs (apply some Loctite to the threads on the tab bolts). Clean the handlebar zincs and ride.

 

[Grog]

Like above the plugs are cheap insurance. Compare a new handle zinc to the one you have. If it's noticably lighter, junk it.

 

[BobP]

Can't tell from photos, but if you do the weight comparison on the big zinc vs. a new one, how does it feel, approx. "half weight", "75% weight "?

I can get two seasons easy on the big zinc, and it's still more than 50% left over in weight. I inspect each year to see if conditions are stable.

No reason to replace good zincs, there is plenty else to spend it on.

Each boat, it's season, and even the particular slip in the same marina will effect the zinc's life, so Yamaha provides plenty IMHO for the worst case. My old Evinrude 150s didn't have enough zince to last a season, had to replace them with larger (longer) ones. My old Johnny 200s only lasted one season.

 

[freddy063]

if it runs good with the plugs don't change them, how offen do you change the cars plugs? Change them when you have to, same with the zincs , but watch them , you can alway change them later.

 

[Grog]

if it runs good with the plugs don't change them, how offen do you change the cars plugs? Change them when you have to, same with the zincs , but watch them , you can alway change them later.

Is your car a 2 sroke? If you do change them, do it after you burn off the fogging oil.

 

[freddy063]

no my car isn't a 2 stroke but my snowmobile is and I haven't changed plugs the it for a few years now, and it runs great still, as long as I treat the gas in the off season. But what do plugs cost ? 2 bucks time 12 I guess that not to bad, to make sure.

 

[JUST-IN-TIME]

my recommendation is

up grade to platinum or iridium plugs
platinum last about 500 hrs, ir 1000 or more

what you do is just clean them with carb cleaner

plugs have come a long way

but at $4 a plug cheap ones, it is sometimes not worth the time to clean

 

[HMBJack]

The zincs you really want to change the ones you can't see.

Take engine cover off. Take the black plastic cowling, on the back, off - you know - the one covering the spark plugs held on with the 4 allen nuts.
Next - look in between the spark plugs. On a V6, there are 4 wine cork sized zincs mounted in between each spark plug - two on each bank of three cylinders. IMHO - These zincs are the ones that wear out the first and should therefore be replaced first. I think they are held in place with 10mm bolts. Good luck!

 

[HDGWJOE]

On the zincs BobP hit the nail on the head... weighing them will give you a good idea of how much is left after the season. Zincs are getting pretty expensive... why throw good zincs away.

On the plugs... I use to change mine regularly every season until recently. Then in 2006 one of my new plugs(NGK) went bad early on. Wasn't even firing. In 2008 it happened again. So now I plan to go at least 2 seasons before changing them... maybe 3 if they look good. I'll pay more attention to fuel burn and acceleration as an indicator. That said I always have a full set of spare plugs on board.