Oil leak from head cover gasket

Hi everyone,

I noticed my bike is leaking oil from the head cover gasket on the right side of the motor from this spot with the red circle: https://imgur.com/a/X9vFfd4

What do you guys recommend that I do? Remove the head cover and install new seal?
Or is there something else I could try first?

Thanks!

 

Hello @ddanielf , your terminology is incorrect. The oil is leaking from the valve cover gasket, big difference.
Pull the valve cover off, if the gasket is still supple it can be reused. If the rubber is hard you should buy a new one.
Even when installing a new one its recommended to apply some gasket sealant at those 1/2 moons in the gasket.

If you have feeler gauges it doesn't take long to measure your valve clearance while the cover is off.

 

Another quick tip—OFTEN there is a sharp burr on the corners. I HIGHLY recommend you get a fine machinists file and just dress the burr off before adding a drop or rtv. Don’t file the daylight out of it, just kiss it enough to remove the burr. Otherwise, it will cut through the new gasket in short order and you’ll end up having to replace it again,

yes, while the valve cover is off, check the clearances while you’re right there. Also, along with a new gasket—make sure you get new valve cover donuts too

 

And don't overtighten the donut bolts.

 

Thanks for all the good tips. It's my first try doing this - wish me luck

 

In many cases, the valvecover GASKET is fine, it's those 12 rubber "pressure washers" (on the cover hold-down bolts) that---over time---harden and/or shrink, and then then can no longer exert enough pressure down onto the valvecover to force the valvecover gasket to create a good seal..........some people attempt to "overcome" this issue by tightening the v/c bolts more than specfied, and end up braking the camshaft bearing caps (!). The correct torque for those bolts (with the rubber washers installed) is 7.2 ft-lbs.; do not exceed! Check those rubber washers!

 

So should I check those first before replacing the valve cover gasket? See if it still leaks after the replacement.

 

I would check both........as Simmy noted, if the actual v/c gasket isn't supple, then it's toast and needs to be replaced. Ditto for the pressure washers. And Dave is also correct about the sharp edges/burrs on the cutouts in the right side of the cylinder head. So measure twice, cut once!

 

Alright. Thanks for the help!

 

Hi everyone (again)!

I finally started working on my bike and I have some questions.
I've measured the valve clearances (as suggested) and this are the results (I have two measurements cause the gauge feeler only had the sizes for the extremes (i.e. 0,10mm, 0,13mm, 0,15mm 0,18mm 0,20mm 0,23mm), so the correct size is one of those 2 measures):

From the bike's left side to right:
EXHAUST: 0,21/0,22 0,16/1,17 0,16/0,17 0,20/0,21
INTAKE: 0,11/0,12 0,11/0,12 0,11/0,12 0,11/0,12

Do you think is necessary to change the 2 underlined on the exhaust side?

Also, I checked my valve cover and noticed that the half moons come off - is this normal? https://imgur.com/a/2RvJQjF

 

Barring a likely typo on exhaust #2, you’re ok on everything.

Halfmoons. Yes they tend to squeeze out. I make sure to clean the mating surface with carb or brake cleaner that will not leave an oily residue—- I want it perfectly dry. Then a light thin line of RTV for installing the gasket. Let it cure, gooD to go. Do you get a new gasket.... did you get new donuts for the valve cover bolts?

 

Ups! yes, it's a typo indeed

Regarding half moons, I still haven't removed the gasket from the cover, but seems like the half moons will get detached when I do - I'm not sure if they are broken and if I should get a new cover or if this behaviour is normal. I'm a bit afraid this is where the oil leak came from and not the gasket.

Yes, I will get new donuts for all the bolts. Problem now is that I cannot remove the outer bolts from the cover - they're stuck it seems - any advice to remove them safely?

 

The half moons are molded in as part of the gasket

the valve cover bolts have a shoulder that you have to press through the donut. Th donut is stuck in the hole in the valve cover turn the cover upside down to to push things out, or just pull harder

 

I'm such a noob
Alright, thanks for the great info!

 

No prob! Asking and learning is what we’re here for

 

Hey guys,

So, I've just drove my bike for the first time since I've replaced the gasket and bolt donuts, and to my surprise it's still leaking oil!! from the same spot
See images (red circle is where it build ups and where the leak is - I think -, red arrows are where it splatters when driving): https://imgur.com/a/IvBCom3

Any ideas of what the problem could be?
Thanks

 

My daughters XJ750 leaks in the same way on the left side. I have replaced the gasket and donuts once. I figured my first fix was not effective and I was just going to try again. More care, more attention to detail, and probably more RTV

Of course, when I get it apart, it will probably require replacements. Maybe I'll just order the donuts now

 

did you put some gasket goop on the half-moons? If no then there’s your leak

 

I ended up not applying the rtv cause I thought new gasket and donuts would do the trick. Apparently not..
I will open it again and put some rtv where is leaking. Hopefully that will fix it.

 

Update: I've opened the cover again and applied rtv. It still leaks but it's a much smaller leak. So I guess it's a matter of adjusting how much rtv I put. I was afraid of putting too much and some coming out inside the motor.
Plus, I've just opened the cover and just cleaned where I applied the rtv. Didn't clean the gasket and the cover throughout and now I see small leaks in other places. I guess this is something you should do to get a proper seal.