Hi, Is there any new information to fix the left-side oil leak for good with new parts, mods, etc?
Thanks

As long as there is no covers cracked, threads stripped, yes, new gaskets.

Thanks, Hub

My 2006 14 had the left side valve cover leak. I took the bolt out and added a washer to it. I had it for 6 years and it never leaked again. From what I heard, the threaded hole on that side wasn't drilled deep enough and the bolt would bottom out. A washer fixed it. I suppose a shorter bolt would do the same thing.

* Last updated by: mokaw on 4/5/2024 @ 7:11 PM *

I replied to your PM, NKX.

My 08 leaked oil from the LH side of the valve cover after one year. It’s a frequent problem caused by the first valve cover gasket that was used on the Gen1 being too thin. By year two, my 08 was needing oil to be added between 2000 mile oil changes. Oil was leaking down the LH side and down to the bottom of the header pipes during storage.

First check if the valve cover bolts are torqued. Tighten them in the correct sequence shown in the last picture on the link below. Mine were all loose when I checked them after year one. Tightening to correct torque might help if the bolts are loose. However, once oil has found its way past the gasket, it’s probably going to continue to seep out.

A quick remedy is to remove all the valve cover bolts and place a washer under each. Then torque each bolt to spec. It might help but I kind of doubt it after 16 years if that’s how old the gasket is. The washer fix seemed to reduce the need to add oil on my bike between services but it didn’t stop the leak. DO NOT over-torque the bolts or the threads in the engine will strip and then you’ll really have a leak.

http://zx14ninjaforum.com/messages.cfm?threadid=91DAF396-D56B-84E2-1CB7DC17E5343386&searchTerm=head%20cover%20gasket%20leak&page=1

If you don’t want to screw around, just replace the head cover gasket, ring-os and head cover bolts. Those parts have been updated since 2008. That will stop the leak.

http://www.zx14ninjaforum.com/messages.cfm?threadid=9C95C90A-D56B-84E2-1DF3FD33B0925047

While the head cover is off, you should check your valve clearances. I’ll bet they have never been checked since it seems likely the head cover was never removed. DO NOT force a feeler gauge between the lifter bucket and cam. This will cause scoring of the bucket and lead to corrosion. …and buckets are something that really should never be replaced unless it’s absolutely necessary.

http://www.zx14ninjaforum.com/messages.cfm?threadid=D659042A-D56B-84E2-1C5A7BC825184613

It’s up to you if you want to do it yourself or bring the bike to a shop for this. Anyone can check the valve clearances but adjusting it is a pretty involved procedure. Unless you have some mechanical experience or a deep interest like I did, you might want to search out a highly reputable shop to do this. LOL if you bring it to a shop, I’d still direct the mechanic to my tutorials!! I’ll bet many pros have used them.

Good luck whatever you do. No need to fret if the valve clearance has never been done. Lots of bikes have never had a valve clearance adjustment. It should be done but it seems the clearances wear in and stop wearing after about 40,000 miles. I never heard of a 14 suffering engine damage from lack of valve clearance adjustment, it’s just something that should be done for optimum performance and absolute safety.

LOL otherwise, torque the bolts to spec in proper sequence and let it leak. Add oil as required!! The oil leak isn’t hurting the engine as long as you keep enough oil in it. Mine used to make a 400 mile highway trip and after that, it was real low but still visible in the sight glass, barely. Don’t run it hard on low oil. Don’t over-torque those bolts, that won’t solve the problem and will lead to threads stripping, a problem that will be very hard to fix. Steel bolts, aluminum head, the female threads are going to give in that situation and then you’ll really be screwed. Actually I think the female head cover bolt threads on the 14 might have a bottom that is meant to help guard against over-torqueing but I would certainly not suggest putting that to the test. I stripped the head cover bolts on my first bike when I was a teen and it was a problem.

View from LH side of the bike: The throttle adjuster cable is in the lower RH of this pic. I'm sure you can just thread it back in but you will need that tension spring and it looks like a washer too. Order parts online. In my experience, it usually takes weeks for parts to be delivered. I believe they have to be shipped from Japan.

Lower left on this one below. Very simple mechanism, you just need to have all of the parts. Check the service manual for a parts breakdown.