Water in Plug Wells - Prevention, a possible solution

[2daMax]

It is notable that our coils get corroded due to water entering the plug wells and being retained. Here is one possible solution, after trying it for 8k km in a tropical weather with thunderstorm weather and running through flooded streets....multiple times.

I have checked both most left and most right plugs and coils and no sign of corrosion or even water marks. These 2 plugs are the most notable for water ingress. As a reference, prior to this Orings, I did discovered my right most has water ingress, with brownish marks indicating water retention, plus a badly corroded HEX on the plugs.

Using O-ring to place in between the engine's wells opening and plug coil's "umbrella" (i hv no better word to describe). Shown below is the Oring in a pre-installed manner.

Below shows as installed.

The Oring is Viton material. Recommended to grease the Orings with high temp grease for better sealing. In my case use Krytox grease.

Dimensions: OD 33mm, thickness 2.95mm, ID 27mm ( measured with a caliper which is not the best tool for flexible things)

Oring info, commercial: http://www.rubberstore.com/catalog/as568-orings-chart.php
Select "914". AS568 number.

 

[stutrump]

Thanks 2daMax. I remember riding in "black rain" when i lived in Hong Kong so I know your advice on wet weather is well tested. Good idea. I'll try the O Rings. Another good idea is to remove the metal sleeves from the coils. The bike runs fine without them and it makes removing the coils much easier because they wont be all rusted up in there

 

[Checkswrecks]

Another thing which works is smearing the existing top rubber seal with dielectric grease.

 

[2daMax]

Thanks 2daMax. I remember riding in "black rain" when i lived in Hong Kong so I know your advice on wet weather is well tested. Good idea. I'll try the O Rings. Another good idea is to remove the metal sleeves from the coils. The bike runs fine without them and it makes removing the coils much easier because they wont be all rusted up in there

I didn't realize or noticed the metal sleeves on the coils. All I see is plastic on the externals. Is it inside?

 

[Xclimation]

I'm not a fan of this design of coils on plugs vertically recessed. I had a Dodge Ram that was the same way. At least once a year when I would wash the engine; Water would definitely fill the plug recesses (or whatever they're called) It would cause the engine to run rough. Even if one or two of the recesses had water in them. And that was with me being pretty careful.

And we have an "Adventure bike".....

Thanks for the O-ring info.! I'm going to do this in a couple of thousand miles when I change my plugs.

 

[2daMax]

Here is the vendor where the Orings came from:

http://www.atlanticrubber.com/WebComp/Catalog/Public/o-rings2.asp?mat=3

Look for -914. Not sure if they sell it 4 pcs per time but their quotation form doesn't have a MOQ.

They are located in MA.

Viton rubber can withstand up to 210C and resist oils and chemicals.

 

[stutrump]

2damax
Look more closely. Each coil has a metal sleeve around it with a slit the full length of the sleeve. Get something under that sleeve to lever it off. Easy. Maybe yours are so rusted that it blends into the colour of a dirty coil??

 

[stutrump]

Hopefully there is a pic attached here. If you look closely you can see the metal sleeve..along the slit of the metal sleeve is a rusty brown stain which is actually all the rust and dirt UNDER the sleeve

 

[WJBertrand]

What about spraying the coil sleeves with ACF-50? Perhaps squirt a little down into the spark plug wells after installing the plugs as well?

 

[Nig5]

What about spraying the coil sleeves with ACF-50? Perhaps squirt a little down into the spark plug wells after installing the plugs as well?

I use ACF 50 during the winter and usually spray some on the rocker cover but think I will be spraying a lot more now to be honest it never seemed as if there was much water or mud on that part of the bike.

 

[2daMax]

Hopefully there is a pic attached here. If you look closely you can see the metal sleeve..along the slit of the metal sleeve is a rusty brown stain which is actually all the rust and dirt UNDER the sleeve

Ahh...I didn't realize it was metal. Mine is all like new looking. I don't feel the sleeve is in the way or anything during removal or reinstalling. The water staining part is actually much lower for my coil, and is below the sleeve, on the right most coil (the one that had water ingress). But thanks for posting the picture to help me understand. The next time I open them up, I will look closely.

 

[Checkswrecks]

What about spraying the coil sleeves with ACF-50? Perhaps squirt a little down into the spark plug wells after installing the plugs as well?

ACF50 is safe for electronics. In aviation it is fogged into avionics compartments.

 

[worncog]

Good stuff here. Used O-rings in the plug wells of my C10 to keep out moisture, as it has the stick coil modification.

Definitely want to use Viton O-rings, as they handle fuels and other elements much better.

 

[RCinNC]

This was one of those posts that made me to "hmm, maybe I should go check this", so today I pulled out the plugs. Sure enough, from the left, the Number 1 plug and the Number 3 plug both showed signs of rust and corrosion. I cleaned them up and checked the gap (two of them are out of spec). I'm going to use the dielectric grease and the ACF-50 when I reinstall the plugs, which brings me to my question. The service manual calls for NGK/CPR8EB-9 plugs. There's no mention of whether or not they should be resistor plugs. The ones I pulled have an "R" on them, so I'm assuming they're the resistor type. These plugs were installed during the valve check by the shop, so I didn't select them. I looked on Amazon and see that they list a CPR8EB-9 plug, plus they list one with that model number as a resistor plug. Which is the correct plug to install?

 

[taskmaster86]

Great Idea, Thank you!

Yamaha probably should have done something like this from the factory!

 

[Checkswrecks]

This was one of those posts that made me to "hmm, maybe I should go check this", so today I pulled out the plugs. Sure enough, from the left, the Number 1 plug and the Number 3 plug both showed signs of rust and corrosion. I cleaned them up and checked the gap (two of them are out of spec). I'm going to use the dielectric grease and the ACF-50 when I reinstall the plugs, which brings me to my question. The service manual calls for NGK/CPR8EB-9 plugs. There's no mention of whether or not they should be resistor plugs. The ones I pulled have an "R" on them, so I'm assuming they're the resistor type. These plugs were installed during the valve check by the shop, so I didn't select them. I looked on Amazon and see that they list a CPR8EB-9 plug, plus they list one with that model number as a resistor plug. Which is the correct plug to install?

The R in "CPR" means the OEM is a resistor plug.
https://www.ngk.de/fileadmin/Dokumente/EN/downloads_not_used_in_download_area/ngk_zuendkerzen_code_en.pdf

 

[RCinNC]

Got it, thanks Checkswrecks. Fortunately, I ordered the right one.

 

[worncog]

Every model has some 'shouldabeens'. My TTR250 Yamaha has a plug PUSHED into the head to cover the no longer used decompression release. Most of the 'shouldabeens' have been recovered by ingenious individuals with component substitution and metal forming skills. Head plugs, starter chains, cruise controls, wheel swapping,...

Seems like the second Gen S10 is better than most in the 'shouldabeen' category.

 

[RCinNC]

I'm curious, are there drain holes in the spark plug recesses?

 

[2daMax]

I place a endoscope in the wells and do not see any drain holes.