Unpleasant Surprise

[RCinNC]

I may have replaced them on the first valve check, but I think I skipped it on the second and I definitely skipped in on the third. This time around it was almost 50 bucks for just those six pieces.

It probably is just a bad or unseated gasket; I can't find anything obvious that caused the leak. I know that the gasket was still doing it's job 10 months and 6200 miles after it was installed, because that's the last time I changed the spark plugs and all was well then. Like I said earlier, a gasket is leak-free, right up until it isn't.

One thing I found weird, and that made me think there might be an underlying problem, is that three out of four tube seals are leaking, but not the fourth. Even though they're connected by runners on the gasket, they're still really four individual pieces. Having three of them start leaking individually just made me wonder. And the fact that a second leak appeared later at the front of the engine, after I discovered oil in the plug wells, that was bad enough to leave drops of oil on the floor made me really wonder.

Off to the shop tomorrow to get something scheduled.

 

[RCinNC]

Because I always hate it when a story ends on a cliffhanger, I'm updating my thread to say that yes, it was a leaking valve cover gasket, and the replacement gasket fixed the problem.

 

[Minuteman_Norm]

Looks like I have the same issue, just not as pronounced on the outside of the engine.

2013 with almost 71K miles on it, valves checked & adjusted with spark plug change just under 20K miles ago at 51.8K miles done in December of 2022 at my local Yamaha dealer. They charged for a valve cover gasket and rubber mounts so I'm assuming they changed the gasket upon reinstall. No issues until I recently started having issues with misfiring and the engine not wanting to idle properly and feeling low on power as if it were running on only one cylinder.

Today I finally cracked into it and found oil on 2 out of the 4 spark plugs, the two left spark plugs when looking from up top, and the corresponding plug wells had oil in there.

First plug: Soaked in oil, also looks like there's a piece of gasket material on the plug as well


First plug well: Soaked with oil and looks like a tore gasket? The coil stick looked like it had some grease on it when I pulled it out so I initially thought the grease had melted and it had leaked everywhere. But after pulling the plug it it looks an oil leak, seems to be confirmed after reading your thread.



How would you suggest cleaning out this well? I tried packing it with some paper towels, and then threading in the dried off plug and running a shop vac. Any recommendations?

2nd Plug:


2nd Plug Well: Apologies for the out of focus, was difficult getting the photos with my cell phone.


The third and fourth spark plugs came out clean of oil. However the 3rd well was very dirty. Not sure if it's rusted from prior water intrusion or dried up oil from a previous issue. I have the same question from earlier, how should I clean this out? Should I? Definitely doesn't seem normal when compared to how clean the 4th is

3rd Well:


4th Well: Perfect in comparison.


Spark plugs lined up (I had already wiped down the first plug)


Coil Sticks: They all seemed to have some sort of grease on them when they were removed, but no grease or o-ring at the top like I've seen done before in other threads. The first two coils didn't seem to be soaked in oil like yours were, but the 2nd coil was very dirty, and the 3rd coil is very dirty as well and seems almost burned. Not sure if from heat, or water or chemical damage on it. I'm thinking it should be replaced. Should I do all 4 at this time too? I've got NGK CPR8EAIX-9 spark plugs and the corresponding terminal caps coming in Tuesday.


@RCinNC did your valve cover leak seem to happen overnight or was it a gradual sort of situation? Do you think my and/or your valve cover gasket failing be due to an issue installing? I read your PCV theory and wonder if you've had any thoughts on it since.

 

[RCinNC]

The actual leak from the valve cover itself happened pretty much overnight. Before I discovered the leaking valve cover gasket, I'd already discovered oil in the spark plug wells during a spark plug change, which I initially thought was broken down Belray grease that I use to seal the spark plug wells. A couple days after I'd done the spark plugs, I came out one day and saw some small oil drips on the floor under the bike, and followed that back to where it was dripping out of the valve cover gasket. Prior to that day, I'd never seen any oil drops on the floor of my garage.

I can't say for sure if the leak was due to bad installation. My initial thought would have been no; that particular valve cover gasket had been installed in Sept 2021, and the leak wasn't discovered until March 2024. I had previously changed the plugs on 07/14/22, and there was no leak at that time. It took around 30 months since the installation of the valve cover gasket for the leak to appear; my initial thought would be that it should have leaked before then if it was a bad installation, but really, I couldn't say that with any certainty.

My thoughts on my PCV valve theory is that I was full of crap, as another member here informed me that there was no PVC valve in the valve cover, and the hose was a simple breather hose.

When I cleaned out my spark plug wells, I left the plugs in place and sprayed the wells with WD-40 to dilute the oil. Then I sucked up as much of the diluted oil as I could with a Mity Vac vacuum pump. Once that was done I took some small pieces of thick paper shop towels and stuffed them down gently into the plug wells with a small dowel rod to absorb whatever oil was left in there, and removed the towel pieces. After it was as dry as I could get it, I blew out the wells with compressed air and then pulled the plugs.

 

[Minuteman_Norm]

. . .

When I cleaned out my spark plug wells, I left the plugs in place and sprayed the wells with WD-40 to dilute the oil. Then I sucked up as much of the diluted oil as I could with a Mity Vac vacuum pump. Once that was done I took some small pieces of thick paper shop towels and stuffed them down gently into the plug wells with a small dowel rod to absorb whatever oil was left in there, and removed the towel pieces. After it was as dry as I could get it, I blew out the wells with compressed air and then pulled the plugs.

I appreciate the follow up information. Thanks for the ideas and tips on the clean up. I hadn't thought of using a Mityvac to help remove fluid from the wells for clean up, good idea!

Thanks for spending the time to share.

 

[Highwayman]

Id personally leave the plugs in, spray carb clean down the holes and with a shop rag over blow compressed air down there. Do that a few times and they'll be good as new.

 

[RCinNC]

If anyone is interested, this saga is continuing over at this thread: https://www.yamahasupertenere.com/index.php?threads/bad-o2-sensor.36138/#post-548044