Cleaning spark plugs...

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ChasB

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I've got 16, so I'm looking for shortcuts.

First I'll do the regular visual inspection and check the gap with a feeler guage.

I was thinking of using my ultrasonic cleaner. There's a few YouTube videos. But anybody had a bad experiences with doing this..?

I was also thinking of doing it using diluted Gunk, and then rinising throroughly later. Or is that a really bad idea..? :o

gunk.jpg

Here's the data sheet https://img0.fastenal.com/productimages/supplemental/product_docs/0691446.pdf

Cheers! :D
 
I'm sure that an ultrasonic cleaner or Gunk, providing it's removed with a little meths/alcohol/acetone won't do any harm. In fact, you could just use the meths and forget the Gunk.

However, I'm not convinced that anything other than a quick swipe with a bit of emery paper/SWMBO's emery board and a gap check does any real good unless the plug is so oiled/carboned-up that it is shorting out, in which case there is something wrong with the engine which needs to be investigated.

Richard
 
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Thinking back to checking plugs on cars, anything other than a bit of beige deposit isn't normal, and this isn't soluble in organic solvents. As Richards says, anything that Gunk or another degreaser will remove indicates a problem that is likely to require the application of painful amounts of cash.

I rather think the act of resetting the gap will do all the cleaning necessary, though a bit of emery won't do any harm.
 
I think so.

If they are gapped correctly and working, leave 'em alone!

I keep an elderly but low milage Mazda Premacy MPV in Wellington. I service it every year as it stands for long periods with only occasional use by my son. When I checked the plugs they were clearly the OE ones, stamped Mazda and with fixed top connector studs, not threaded ones. They looked like new and were working good.

Manufactuers service sheet says change at 30,000 KMS. The car had done 71,000 KMS on the OE plugs.

I put new ones in, quite expensive, for peace of mind.
 
Unless your engine is like mine and calls for iridium every few years (extortion)....just replace them every year or 100 hours. Cheap as chips and no point taking a chance on such a thing. The wife and kids won’t thank you for it when it goes wrong for the sake of a 2 figure sum of money.
 
The only plugs I clean are on two strokes where they've got oily because it won't start for some other reason or it's idled far too much.
Then I just squirt them with carb cleaner.
Most attempts at physical cleaning probably do more harm than good.
As QBHoy said, they are quite cheap really.
 
TQA said:
Basically don't clean by any physical means.

OK to burn off any petroil on the stove
Click to expand...

Well-a sweeping statement!

Champion used to sell a little toolbox kit for cleaning plugs-tiny wire brush, prodder and feeler gauge as well as supplying garages with sandblast cleaning and testing machines.

Before that you could take your three piece plug in bits and sandpaper the carbon off!

Modern plugs rarely need such attention, but should I find a plug bridged by a blob of carbon between the points, rest assured I shall physically remove it!

I still have my special steel tube, blocked at one end, 10mm plug thread at the other filled with 15 thou straight steel wires.

When the chemist would supply ether, a few drops were poured inside, the plug screwed in and shaken vigorously.

This would clean the extremely hard carbon produced by Castor racing oil from the inside of the expensive Speedway plugs. Retracted gap type too, so tricky to adjust the gap.

At 15 quid a pop twenty five years ago, I cleaned 'em!

Once ether became difficult to get I found Easystart almost as effective-and easier to use.
 
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I used to grit blast spark plugs in a machine supplied to the garage I worked at to clean the plugs. The machine would also test the spark under pressure from the garage air compressor.

I did/do have a little grit plug cleaner which will run from a 12 VDC battery left over from my car tuning days.
 
Rogershaw said:
I used to grit blast spark plugs in a machine supplied to the garage I worked at to clean the plugs. The machine would also test the spark under pressure from the garage air compressor.

I did/do have a little grit plug cleaner which will run from a 12 VDC battery left over from my car tuning days.
Click to expand...

I remember those things.
But these days I think TQA is not badly wrong.
Modren plugs should not need cleaning, they run hot enough to self clean and damaging the ceramic surface or embedding traces of metal in it won't be a good thing.
 
lw395 said:
I remember those things.
But these days I think TQA is not badly wrong.
Modren plugs should not need cleaning, they run hot enough to self clean and damaging the ceramic surface or embedding traces of metal in it won't be a good thing.
Click to expand...

ALL spark plugs have a heat range, determined by the insulation around the centre electrode. Long thin insulation, plug will run hot, short fat insulation plug will run cooler. It is all to do with the plugs ability to lose its heat to the cylinder head. A cold running plug in an engine which is overcooled, like many outboards, may foul the plug through not getting hot enough to burn off deposits.

I said modern plugs rarely need cleaning, or in fact any attention.

But, should you get a duff one, miles from being able to find a replacement, knowlege of how to get one working again could be invaluable.

Could save a long row....................
 
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