Cleaning spark plugs

[boristhebold]

Probably a question for those with two stroke engines LOL ... what's the best product for cleaning spark plugs to remove the carbon and crap that builds up over time. ?

[plymjack]

Wire brush & WD40 or the like...

Interestingly on our 1996 8HP 2-stroke Mariner we had an impeller failure which overheated one of the HT leads. I repaired it and it was fine but noted it was the original.
So I spent £20 on new leads and £8 on new sparkplugs...... as soon as I started the boat my wife immediately noted the huge difference.

The engine ran a lot smoother, quieter and less vibration - it was a step difference. Can say any change in speed or economy as yet but the engine is running a whole lot better.

[jeffstevens763@g]

New plugs for what they cost IMO

[Poly]

Boris - I know you have a particular issues possibly linked to a long slow speed passage to/from the sea, but I’m not convinced sooted up plugs are normal. I would have expected sophisticated DI tech would make it less likely and that unless you have changed marina recently that on a boat/engine as old as yours you’d have seen it before. So Id be concerned something else is off like mix, timing, oil injection settings etc.

[boristhebold]

Originally Posted by Poly

Boris - I know you have a particular issues possibly linked to a long slow speed passage to/from the sea, but I’m not convinced sooted up plugs are normal. I would have expected sophisticated DI tech would make it less likely and that unless you have changed marina recently that on a boat/engine as old as yours you’d have seen it before. So Id be concerned something else is off like mix, timing, oil injection settings etc.

Yes ive seen it once before last summer when I was often taking the long slow (6 knots) trip round the back of brownsea island back to holes bay. Started misfiring and rough, plugs were changed and back to normal. Apparently it is a common fault with 2 stroke engines. Have changed plugs now and all is better.

If you consider spring and summer months when 10 knot speed restriction in place then every time I go out and back from Holes bay I have a total of say 30 min at 6 knots and say 40 min at 10 knots, thats adds up in a few months. In the winter well from autumn restriction goes in poole harbour main channel so its better.

Am going to change plugs every 6 months and add some engine cleaner fuel additiative every couple of fuel top ups which should do the trick.

[Maximus]

Originally Posted by jeffstevens763@g

New plugs for what they cost IMO

I agree!...Why spoil the day for pennies?!....if they keep needing to be cleaned/changed you have issues that need sorting.
....Or change you're launch site
I had old Blue Band 2smokes for years and never had problems in that regard even at trolling speeds...a good rev now and then does help!

[Poly]

Originally Posted by boristhebold

Apparently it is a common fault with 2 stroke engines.

it is - but unless I'm mistaken you've had that engine for several years but only had this issue twice?

If you consider spring and summer months when 10 knot speed restriction in place then every time I go out and back from Holes bay I have a total of say 30 min at 6 knots and say 40 min at 10 knots, thats adds up in a few months.

I'd have expected the high speed suff in between to burn off most of the soot from each time. Now if its got so bad its misfiring you may not get that cylinder to work properly enough to self clean but to my mind it shouldn't be a progressive problem.

Am going to change plugs every 6 months and add some engine cleaner fuel additiative every couple of fuel top ups which should do the trick.

if the issue is going to be much less in winter (because the speed limit is different) I'm not sure it makes sense to change every six months - not better to inspect every month in the summer and change as necessary?

[spartacus]

Spark-plugs should be good for a season, but I clean them too. I use a soft bristle brass wire brush to remove any carbon. If you want to spray anything on them, then use brake cleaner which evaporates. Always nip up the head of the electrode that the HT lead connects too, it always seems to be working loose.