Salt deposits on lower two plugs

rjbathgate · 17 December 2009, 17:48

Hey,

Recently I noticed salt deposits (dried chrystals) sitting around the two lower spark plugs in my outboard (Mercury 60hp 2stroke).

See attached images - apologies they're terrible and appreciate you can't actually see much!

The chrystals scrubbed off really easily but it's not right is it....?! although it's not really doing much since it's just chrsytallising on the outside of the plugs, on the paint...

A while ago, the telltail pipe came out of it's outlet hole and was outletting into the cowling area around the bottom, until I realised it was doing that and I fed it back into the outlet hole... as a result, there would have been some salt walter (for I was out to sea) splashing around inside....

After that I gave it a good dosing of corrosion inhibitor (WD40) and it all looks good - apart from just around the plugs...

And I am not 100% sure that the two are directly linked - i think ive sen some (not as much, but some) salt deposits around the plugs before this telltail went nuts...

Any thoughts, most apprecaited....

Cheers

jyasaki · 17 December 2009, 18:01

That's a pretty likely spot to dry out any salt water that gets in, as the plug will conduct heat from the cylinder head.

Is the buildup recurring, or is it a one-time thing? If one-time; I'd say that pumping salt water in under the cowl (from the tell tale) would be the culprit.

If it's on-going, you're still getting water in from somewhere - try spraying it down with a hose and seeing if you can ID where the water is ingressing.

FWIW, I'd be a little careful about spraying down with WD-40 (or any other flammable carrier based CI) while the engine's warm. Stuff goes up like you wouldn't believe (or at least used to.)

jky

rjbathgate · 17 December 2009, 18:10

Quote:

Originally Posted by jyasaki

That's a pretty likely spot to dry out any salt water that gets in, as the plug will conduct heat from the cylinder head.

Is the buildup recurring, or is it a one-time thing? If one-time; I'd say that pumping salt water in under the cowl (from the tell tale) would be the culprit.

If it's on-going, you're still getting water in from somewhere - try spraying it down with a hose and seeing if you can ID where the water is ingressing.

FWIW, I'd be a little careful about spraying down with WD-40 (or any other flammable carrier based CI) while the engine's warm. Stuff goes up like you wouldn't believe (or at least used to.)

jky

Cheers for the reply...

That makes sense now, being the warmer parts... figure its the lower two as they got the brunt of the tell tale going crazy...

Now I've cleaned it all i'll see if it's reoccuring... and if it is, try find where its coming in --- the cowling lid doesn't fit incredibly tightly to be honest, but wouldny say enough to cause major ingress...

Humz will see..

Yeah, always wait a wee while before spraying with WD40 and let it dry/air out before putting lid back on so it's not sitting 'oil damp' inside until next time we go out....!!!

spartacus · 17 December 2009, 18:17

There should be drain holes on the lower engine tray. Check these are clear. You can give the tray a spray with an engine degreaser, clean thoroughly with a toothbrush and then rinse off with hot water. Dry it, then give it a liberal spray with WD40 or better still Quicksilver Corrosion Guard. While you're doing that, check for salt crystals on the engine block itself especially around the gaskets. You may have a leak on the block itself, or from the thermostat.

m chappelow · 17 December 2009, 19:18

it is likely the tell tail pipe coming loose thats caused it but as sparticus said the drain holes need to be free,,though i have seen some engines that have had problems with water and spray coming back though the holes in certain sea conditions and set ups . with some engines ,know one person that placed a small loose piece of wet suit material over one hole to stop spray up onto on the plugs ,

Hightower · 17 December 2009, 21:18

I had a Merc 90 4Stroke and the Pitot tube came detatched and would introduce water only at speed. Would be worth checking as well.

rjbathgate · 17 December 2009, 21:39

Quote:

Originally Posted by Hightower

I had a Merc 90 4Stroke and the Pitot tube came detatched and would introduce water only at speed. Would be worth checking as well.

as far as I can tell it doens't have a Pitot tube....

EDIT: i was just being blind, and have found the tiny hole at back of gear case...

it's just a tiny hole going into gearcase area...no tube as such... not clogged, but only seems to go about 1inch deep in as far as I can tell... not really sure what im looking for...!

Question: dash has a speedometer, and transom has skimmer (for gps/sonar)... does the speedometer run off skimmer or pitot tube... if the latter, how does it work, because to me, the pitot tube/hole is just that, a hole....

Hightower · 17 December 2009, 21:55

Well on mine (you have to remember it's a four Stroke) the was a tube coming off the front of the cavitation plate area and going into the leg. It ran up the leg and entered the base of the cowel where the gear selector entered. The tube was just lying in the bottom of the cowel under all sorts of things and wasn't very obvious at all. I think I must have pulled it at some point on the tiny bung in the end fell out (never found the bung).

9D280 · 18 December 2009, 10:20

Yeah, as HT says, it's a small hole on or around the leading edge of the gearcase. When I got mine the hose had been snipped about an inch above the fir tree, and so I basically filled it with sealant, folded over & used a mini tie wrap to hold it folded. If it;s not been removed, you should have a small ruibber hose poking out from under the cowl smewhere near the leg.

Speedo on your dash could be one of two types - either a pitot (use with the pipe described above - some have a dedicated pitot similar to your skilnmmer) or an electric one one that uses either the transom skimmer or the NMEA speed data from your GPS.

What goes in the back of the speedo? all wires or tube / tube + wire (if it's lit)

Locozodiac · 19 December 2009, 20:23

Would say that no matter what you do, there will be corrosion, salt formation on metal parts on lower plugs on most engines, worst if you do not constant clean/rinse with fresh water after use. Have even sealed the few lower tray holes thinking avoiding water intrussion, with no apparent results, as there seems to always exist a salty environmet condensation under the hood. Even W40 seems not to work properly as it should. So to minimize corosion & salt formation, have opted for applying several hands of nail polish to new plugs metal parts. Now have cute & eyecatching spark plugs!!

Happy Boating

rjbathgate · 19 December 2009, 21:16

Quote:

Originally Posted by Locozodiac

worst if you do not constant clean/rinse with fresh water after use.

By this you mean only rinsing thru the coolant system with fresh water I preusme?!! rather than hosting the engine!!!

Quote:

Originally Posted by Locozodiac

So to minimize corosion & salt formation, have opted for applying several hands of nail polish to new plugs metal parts. Now have cute & eyecatching spark plugs!!

Sounds flammable to me

Think I need to just give my engine a nice clean out and degrease and just keep on top of it with WD40 (or proper corosion spray when my wd40 runs out...)

Cheers

Locozodiac · 20 December 2009, 01:01

Always flush engine for 5 minutes after each use, including water squirts on engine lower tray as there is always salt water condensation due to engine heat, towell dry and small amounts of W-40 application with brush as not to have W-40 soup on tray, even so plugs tend to corrode specially lower ones. No problem applying nail polish, been doing it for months as I always change plugs every 250 metered hours, like to see them as new as possible. Just a aesthetic issue look when removing cowl.

Happy Boating

9D280 · 21 December 2009, 08:30

Thing is that as sioon as you start, the engine starts pulling air in from inside the cowl. The air inside the cowl is replaced by air being sooked in form a hole (usually at the top rear of the case, but variations do exist) and so if you are in a saltwater environment, you WILL get salt, moist air ingested. The plugs are at one of the hottest points of the engine away form the exhaust ports, so any moisture in the air round there will evaporate leaving the salt behind.......

Loco - I'd leave those drains open - you have a gaping hole at the top of the cowl, and should you get properly "pooped", how will your tray drain?

rjbathgate · 21 December 2009, 08:44

Quote:

Originally Posted by 9D280

Thing is that as sioon as you start, the engine starts pulling air in from inside the cowl. The air inside the cowl is replaced by air being sooked in form a hole (usually at the top rear of the case, but variations do exist) and so if you are in a saltwater environment, you WILL get salt, moist air ingested. The plugs are at one of the hottest points of the engine away form the exhaust ports, so any moisture in the air round there will evaporate leaving the salt behind.......

That does make me feel slightly better - outboards are designed for such environments I guess... an being able to pull it out of water and give it a good rinse eveyrtime is a darn sight more than many other boaties would do, esp those who leave boats in water....