2012 RT Stick Coil Rubber Boots Came Off Inside Cylinder

[freetime2247]

Anybody every had the rubber boots on the stick coils come off inside the cylinders? Went to do my annual maintenance valve check. When I pulled the left cylinder upper stick coil the rubber boot came off inside the cylinder. The exact same thing happened to the right cylinder. Bike has approximately 49K miles and always stored inside. I've owned the bike since late 2014 and about 7,500 miles so I've completed numerous valve checks and replaced the spark plugs a few times. However, I did not add any grease to the rubber boots for reinstallation after my last annual valve check and I rode just 3,500 miles this past year.

Any ideas why both rubber boots came apart? I've also ordered two new stick coils.

[dirtrider]

18 minutes ago, freetime2247 said:

Anybody every had the rubber boots on the stick coils come off inside the cylinders? Went to do my annual maintenance valve check. When I pulled the left cylinder upper stick coil the rubber boot came off inside the cylinder. The exact same thing happened to the right cylinder. Bike has approximately 49K miles and always stored inside. I've owned the bike since late 2014 and about 7,500 miles so I've completed numerous valve checks and replaced the spark plugs a few times. However, I did not add any grease to the rubber boots for reinstallation after my last annual valve check and I rode just 3,500 miles this past year.

Any ideas why both rubber boots came apart? I've also ordered two new stick coils.

 

 

 

Afternoon  freetime2247

 

Yes, I have seen that a few times (not just camhead bikes), most likely caused by not using proper spark plug boot grease on the inside of the stick coil boots at last service.

 

I haven't ever had it happen to me personally as I always use a good quality sparkplug boot silicone grease before re-installing the stick coils. Plus I don't just pull the coils out with a puller, I use 2 padded flat blade screwdrivers to gently (& slowly) pry/work the coils off of the spark plugs after twisting the coils back & forth a little to pre-break the boot to plug attachment loose. 

 

I can't say for sure but in my limited experience the ones that I have seen this happen to were previously serviced without using spark plug boot grease.   

 

[freetime2247]

I've not used grease before however, I will in the future. It took me over an hour per side to get all the rubber boot pieces free from the spark plug housing.

[dirtrider]

15 minutes ago, freetime2247 said:

I've not used grease before however, I will in the future. It took me over an hour per side to get all the rubber boot pieces free from the spark plug housing.

Afternoon  freetime2247

 

I presume that by  grease you mean using a quality silicone based spark plug boot specific, high heat dielectric grease? Never use a regular (non-plug-boot-specific)  grease.

[6speedTi]

I clean up the boot after I remove it and add Dielectric constant grease to the tip and a thin layer on the side of the boot so it slides out easily on next removal. So far so good. 

[freetime2247]

I'll do the same when I get my new boots. Since, I've never added this grease I'm curious why now and why left & right at the same time?

[dirtrider]

35 minutes ago, freetime2247 said:

I'll do the same when I get my new boots. Since, I've never added this grease I'm curious why now and why left & right at the same time?

Afternoon  freetime2247

 

No way to know for sure but probably a combination of original boot age (degrading rubber) many/many heat cycles, plus lack of enough lubrication. 

 

I have worked on a number of high mile older hexhead/camhead bikes & if properly lubricated (protected) they have all come off without sticking or damage. 

[AHD43]

Why both at the same time.....who knows.  I had the same thing happen on my 2012.   I just bought new and moved along.

[poodad]

Same thing happened to one of mine. I did not use grease on the prior plug change, and paid for it.

[009jim]

Can somebody clarify what this "spark plug boot grease" is? Is any silicone grease suitable?

[9Mary7]

3 hours ago, 009jim said:

silicone grease

Dielectric grease......at your favorite auto parts store.

[pwillikers]

This stuff.   https://www.permatex.com/wp-content/uploads/tds/81150.pdf

 

D.R., Thanks for the two screwdriver tip. It works a treat (as my Brit buddies would say).

 

[009jim]

https://www.crc.co.nz/Dielectric-Grease-Blog/7064/#:~:text=There are many common types,protects electrical components against corrosion.

[Lowndes]

Not saying this is the best stuff but it does say "spark plug boots" under "Uses".  WallyWorld has it for $3.05 for a 0.5 oz tube.

 

    

 

 

 

Or, Autozone for a different and SPB-specific application, not recloseable but cheap.  "A little dab'll do ya."

 

 

 

[Mike279]

I have had a couple of instances where the grease has reacted negatively with the boot and stuck like I used glue.  Not sure how or why. Maybe the rubber compound on certain boots?

[6speedTi]

DOW CORNING DC4 works great. Same stuff. Used highly in aviation and marine industry.