Head Cover Gasket Leak Fix

Oil leaking oil from the top left front corner of the engine is not an uncommon problem with the ZX-14. The oil seeps past the gasket between the head cover and the top of the head. This is probably caused by the gasket losing its resiliency over many heat cycles. Some of the oil that seeps out while the engine runs gets burned off of the head pipes. The oil that accumulates on the front and left side of the motor will not burn off but eventually flow to the tip of the oil drain plug protector on the oil pan. The oil loss is usually not drastic, requiring replenishment every 600-1500 miles. If the leak is slower than that, the oil is probably burning off before it is seen anywhere on the outside of the motor.

It has been suggested that the reason the leak comes from the left front corner is because that is where oil in the head flows after shutdown when the bike is put on its side stand. Some owners claim to have prevented such leaks by regularly putting the bike vertical on a rear stand after shutdown instead of tipped to the left on the side stand. This however has not been my experience. The photos below show the bike after being stored level and vertical for two months on front and rear stands.

Oil leaks down the front left collecting at the tip of the left header bolt.

The leak flowed down the head pipe and accumulated at the oil drain plug shield.

The use of synthetic oil could be partially responsible for the leakage. Synthetic oil flows more readily and remains clean much longer. For these reasons, it may have a dissolving effect on the deposits left by conventional oil that accumulated at any loose spots in mating parts of the engine. The leaks that will inevitably happen in an engine may happen sooner after synthetic oil is used.

The head cover bolts have a shoulder which is designed to be tightened against seats in the camshaft caps inside of the head. This creates a definite point where the bolts should stop being tightened. The threads in the camshaft caps are aluminum and they will easily strip if the bolts are torqued too much.

If the head cover shoulder bolts are already drawn up to their seats, a shim under the bolt head will lift it away from their seat allowing for additional tightening. If the shim is .5 mm thick, the bolts will compress the gasket an additional .5mm before the shoulder makes contact with its seat.

The perfect shim for the head cover bolts is a 3/8 in or M10 washer. Any metal washer will do but they come in different thicknesses. Galvanized washers are the thickest. Zinc washers are thinner and Stainless steel are usually thinner yet. Stainless steel seem to be the washers that were most commonly recommended in the forum posts I read. Some used 2 washers per bolt while others used just one.

A head cover shoulder bolt shimmed with 2 stainless steel washers.

A head cover shoulder bolt shimmed with 1 stainless steel washer.

Some owners described their solution to the head cover gasket leak as simply placing washers under the two left head cover bolts and tightening them down again. The other head cover bolts were left alone in those cases. Other owners removed all of the bolts, placed washers under each and torqued the bolts to spec. Still another owner claims that an inexpensive liquid gasket applied between the rubber gasket and the head cover solved the problem altogether.

The following tutorial describes the more complete process of tightening the bolts evenly across the entire head cover. After doing this procedure, I am not 100% satisfied with the results. The leak has been reduced but not eliminated. I will update this tutorial as I take additional steps to fix the leak. At this point, my feeling is that the head gasket and head gasket washers with rubber pads (ring-os) should be replaced. The head gasket’s part number has been changed which indicates that the leakage problem may have been addressed by Kawasaki through a revision to OEM parts. I believe the OEM ring-o part number has also been changed.

Do First:
Remove Lowers, Foremans, ram air covers, Sides, tank fairing (Fairings Removal)

Remove Engine Heat insulator Plate (or open the top to get at head cover bolts).

Tools
1/4 inch drive ratchet
8mm socket
10mm socket
1” extension
3” extension
1” extension
universal adapter
1/4” drive 20-200 in lb torque wrench
3/8” or M10 stainless steel washers (6)

1. Using an 8mm socket, remove the LH fairing hanger or you can remove the main wiring harness from the plastic retainer (step 3, LH Side Subframe Removal).

Pull the main wiring harness aside to allow access to the top of the engine.

2. From the left side, locate the left head cover screws [3], [4]. These are the ones closest to where the gasket leaks.

From the right side of the bike, locate the remaining head cover bolts, [1], [2], [5] and [6]

3. Clean the head cover off thoroughly to eliminate any debris that may fall into a bolt
hole.

The front left bolt is in a difficult position. Use a 10mm ratcheting closed end wrench or universal adapter and a 3” extension to reach it (see Head Cover Removal, steps 1 and 6).

The back left head cover bolt is also a bit obscured by the throttle cables. Use a 1” extension to reach the bolt head from between the throttle cables.

The two RH bolts are easily reached. The middle two bolts are also easily reached if the clean air switch valve has been removed. The photos of my bike show no switch valve and block off plates. If you are not able to reach the front middle screw, the switch valve may be removed or perhaps just the right reed valve cover (See PAIR Removal).

Remove all six head cover bolts using a 10mm wrench cover the holes with tape and bring a bolt to the hardware store to test fit washers.

4. Place one washer on each bolt and thread each through the head cover hand tight.

5. Tighten the bolts evenly a little at a time according to the pattern shown in the illustration below.

Torque bolts in sequence using an accurate 20-200 in lb torque wrench. be very careful to seat the socket squarely on the front left bolt head. The extension and universal adapter make turning the bolt awkward (see Head Cover Removal, step 6).

Torque the bolts to 87 in lbs.

If at any time you feel the bolt meet sudden resistance, the shoulder has bottomed out against its seat. The bolts may receive a slight final torque but do not continue to thread them in deeper than this point.

Install Fairings (Fairings Removal).

Install Engine Heat insulator Plate (or close the top flap).

* Last updated by: Rook on 1/12/2018 @ 9:42 AM *

Another excellent POST!One question here(oh no).....your 'leak' apparently was on your #2 pipe there.You didn't say whether the oil had actually dropped from the gasket up top,or that you just saw the oil on the pipe and such.You said your bike was vertical...your oil deal may be something more sinister possibly?. MAYBE that oil is actually coming from the exhaust valve seat area,dripping down after she's cooled off.You know...escaping from the actual header seal(not the gasket on the header as your pic shows,but up deeper into the exhaust outlet).Just a thought Rook.You know me....curious.I never saw a drip like that ever.That's pretty substantial.You ever get any white smoke out of your exhaust?Even a small amount say,at startup?Possibly it could get into the exhaust port past the valve?Maybe?IDK.It would burn off while running...but flow when sitting...straight down and out of that port?I don't see any oil residue on that one pic of the 'frontal/side' shot of the heat blanket partially pulled back there.None on the lower part of the cover gasket at all.None on the front of the engine above that #2 pipe.

* Last updated by: Grn14 on 12/30/2011 @ 11:11 PM *

I installed a centerstand a couple of months after I got my bike in '07, and bike was vertical on the centerstand every time it was parked. Started leaking 4 1/2 years later.

* Last updated by: alg8er on 12/31/2011 @ 1:48 AM *

The pics of the leak were after the bike had sat for a couple months without running. It never got all the way to the bottom of the head pipes when the bike was in normal use. Would have burnt off long before that. This was a very thin film. Oil just keeps creeping. I am sure it is the head gasket. I can see that the oil is coming from there. If oil was leaking internally past an exhaust valve, I doubt if it would come out of the pipe way up on top. it would leak down to the bottom and burn and yeah you would see smoke. Only smoke I see is steam when it is cold outside.

I don't see any point in putting a second washer on. The bolts are torqued to spec and another washer won't help. I will just replace the gasket and other rubber parts after the end of next season. That is the correct way to fix a leaky gasket. you replace it LOL!!! I like the washer fix though. Def worth a try. Thanks for all your help on this, Grn.

Grn14 took the time to explain the washer fix to me in another thread.

* Last updated by: Rook on 1/1/2012 @ 7:37 PM *

I don't see any oil residue on that one pic of the 'frontal/side' shot of the heat blanket partially pulled back there.None on the lower part of the cover gasket at all.None on the front of the engine above that #2 pipe.

I def see oil originating from the head gasket in the 1st pic. Also see a definite high gloss to the rib above header #2. The bike is stored vertical so the oil flows to center more than it would with bike tilted on its kickstand. IDK why the oil didn't flow down header #1. Must have been something that interfered with the path. There was a film of oil all the way to the oil drain plug guard. This is after sitting from the end of December through the end of March.

Just finished putting the M10 washer on the two left side bolts.
My torque wrench wouldn't fit squarely on the front left bolt. If anyone else is limited with their tools as I was, then this is was what I did to torque the front left bolt as accurately as possible.
I removed the rear left bolt and noted exactly the point where the bolt begins to thread into the cover. This was easy to do. I then marked the bolt side and cover with a marker. The bolt with M10 washer threaded down 6 3/4 turns where it became my idea of finger tight. From there my torque wrench turned the bolt exactly 2 turns when it clicked at 7.5 ft/lb.
I then used the same method on the front left bolt. I found the front bolt would turn 6 1/4 turns until finger tight. Not sure why the 1/2 turn difference but my thinking is the torque begins at the finger tight point so the 1/2 turn difference isn't important. I then tightened the bolt exactly 2 more turns with a box wrench, which is all I could use.
I feel this is accurate enough and should help avoid snapping a bolt as I've heard has happened. Now I just hope the leak has stopped or at least decreased enough to live with it until my 15,000 mile valve chack.

I'm going through the same phase. Only 14k?
I'm getting the newer gasket, new shorter bolts and getting the valve clearance check done. If she continues to leak after that I'm getting a Busa.

I'm getting the newer gasket, new shorter bolts and getting the valve clearance check done. If she continues to leak after that I'm getting a Busa

kak the bolts are a tad too long and they bottom out b4 the cover is at the required torque thus the dreaded valve cover leak. Ive not heard about shorter bolts most here just add a washer to it

OK. Thanks for the reply.

I believe the part # is different after 2010 for the head cover gasket. The 'ringOs" on top are also a new part #. Bolts? IDK if they changed those.

KAK, I think you might as well try the washer fix. Good idea on estimatingthe torque for that pesky front left. I used an extension and a u joint attachment to get on that sucker and I'm sure the torque was not quite as tight as it should but awful hard to tell anything by feel with all that extra attachments on there and all turned at weird angles. {Priority was to not over-torque and strip threads.

Good luck. Mine is at least improved. Last winter it was running down the motor by this time. this winter, nothing. Hope it holds up when the season starts and the motor is actually running.

My leak was fixed under warranty with new bolts, gaskets, sealant, and o-rings. Dealer said bolts, gasket, and sealant all had different stock numbers from originals.

Yeah that's what I heard. I ordered from 2011 but the part numbers where the same with 2009, didn't compare them to 2006 but I'm pretty sure they changed #'s and parts for all previous years. I think but I'm not sure the bolts are shorter. I will double check and let you know. If they're the same length I would just cut them and round them off with a grinder. The washer fix is fine if it is temporary... Long term? I don't know. I was about due for a valve clearance check so I may as well take care of that. Furthermore, kaw changed the gasket for a reason!

I think but I'm not sure the bolts are shorter. I will double check and let you know. If they're the same length I would just cut them and round them off with a grinder.

You could do that but then you are getting back to an improvised fix when there are already parts updated to solve the problem (we hope). IMHO, I would only mod the OEM parts if you are not replacing any of them. If you go with one updated replacement part, might as well replace all the rest of the replacement parts. If you replace some of the replacement parts or mod any of them, if the leak is still present, you will not know if it was the parts you replaced or the mods you did to them.

You are right Rookster! I'm replacing all parts: gasket, o-rings, bolts. I was going to cut the bolts cause I heard the new gasket is not that different from the old one! What do I do if the bolts are the same? Can I just put all my trust in that new gasket? Hopefully, I'm getting the same bolts Alg8r got!

* Last updated by: dragking on 3/6/2012 @ 4:56 PM *

dragking; dealer said new # bolts are shorter than the ones he took out. Hopefully that's what you get. I'm assuming the old # bolt wouldn't be available for that application anymore.

You are right Rookster! I'm replacing all parts: gasket, o-rings, bolts. I was going to cut the bolts cause I heard the new gasket is not that different from the old one! What do I do if the bolts are the same? Can I just put all my trust in that new gasket? Hopefully, I'm getting the same bolts Alg8r got!

The ring-os (that's what they call them) that sit between the bolt heads and the head cover have been revised.

* Last updated by: Rook on 3/12/2012 @ 10:11 PM *

So if I have this right, to fix the leak once and for all..... buy the new gasket, sealant, ring-o's and new bolts (as long as you can verify they're shorter)?
Gotta wonder why they also changed the ring-o's, and how are they changed?

* Last updated by: KAK on 3/12/2012 @ 10:52 PM *

dragking; dealer said new # bolts are shorter than the ones he took out. Hopefully that's what you get. I'm assuming the old # bolt wouldn't be available for that application anymore.

So if I have this right, to fix the leak once and for all..... buy the new gasket, sealant, ring-o's and new bolts (as long as you can verify they're shorter)?
Gotta wonder why they also changed the ring-o's, and how are they changed?

Well the mech forgot to take a pic of the bolts so we can't compare... He told me they were the same though!!! They were ordered off of a 2011 fiche so I'm hoping it's the right stuff. I can tell my old gasket was squished because I can see much more meat between the top cover and the rest of the cover. My take on the valve cover leak is this... I think that some of us got longer bolts and that the rest got the right ones. Alg8r said is started really early (3000 miles I think) mine started some time after 10K miles when I switched to Full synthetic and it wasn't really pronounced. That being said, I think that the gasket and O-rings/Ring O's and sealant have been replaced with better stuff! Little Note about the valve clearance check: I have 14400 miles and all valves where still within spec, the bike sees a good amount of high rpm action, I have missed the redline on several occasions and I like coming out of a turn with a little power wheelie from time to time! Unless you have a valve cover leak that you don't want to fix with washers, wait for at least 20k miles.

* Last updated by: dragking on 3/22/2012 @ 11:56 PM *

Unless you have a valve cover leak that you don't want to fix with washers, wait for at least 20k miles.

+1 Oh hell NO, if there is no leak DO NOT mess with it.

I also agree that you can wait a lonnnnng time to do the valve clearance check. a couple of mine were slightly out of spec at 29,000 miles.

I'll do my second check between 25k and 30k give or take

This is yet another ding against Kawasaki.They need to slow down on theses powerful engines and take there time to build a solid product. I am slowley walking towards another make.

not gonna say it? Hayabusa!!baby!!

Its also a nice bike. Great choice. The engine, I think it is a little more bulletproof. Runs a lot cooler than the 14 and you can see that in the color of the oil when you change it. The busa oil never gets black. Never a leak as far as I have heard from other owners. They do not paint the motor black or put a rubber on it like the 14 so you know it if there is any kind of leak you see it on that bright white silver alum finish. never so much as a slight film.

BIG picture: The busa also has been known to spin bearing and bust out the motor. If you want big bore, that is the risk. I have a lot of confidence in the 14r though and I can't waqit to see the Hayabusa rebuttal some day.