Last summer I upgraded from the ZZR1200 to the ZX14R - a 2013 used but with only 7500 miles on her. I'm at 16k now and the winter months are a good time to take things down for the valve inspection in my household. BTW, I love the upgrade in all aspects and have no regrets.....

Here's the 1st issue - #4 outer intake valve top has a bunch of build-up on top of the valve. Has anyone else seen this?

And I just finished checking all the clearance's - 7 out of the 8 exhaust side need adjusted and 6 out of the 8 on the intake side. The adjustment is only 0.001" on the intake, but up to 0.003" on the exhaust side. What level of a problem do I have? And everyone I have talked to says the ZX doesn't tend to have cam wear issues.

Everything was running 'fine' when I took her down - no noticeable issues at all.

The cams dont wear, the valve seats, guides and to a smaller extent the valve seat do. Gaps get smaller because of the seat wear.

By buildup do you mean there's crud on the retainer/spring/valve interface? Other than good oil should not be much else in there to build up. If its still apart suggest a leak down test to see if the valve seat is bad and blowby is accumulating there. A compression test is mainly for rings but would be better than nothing.

Have not heard of this issue before so whatever it is its not common. It it was me I would do the 2 tests, have an oil analysis done. Probably nothing to worry about.

Now, if you cant get that valve gap into spec that's when it gets interesting ....

Picture would be helpful

I think it was about 18000 miles when I did the adjustment on my Gen1. They were as much as .002" tight. None were .003" though.

About halfway down the page the yellow diagram:

http://zx14ninjaforum.com/messages.cfm?threadid=D659042A-D56B-84E2-1C5A7BC825184613&show=0

There was a guy a few years back who had valves so out of spec he was unable to adjust them into spec. Do some searching and you will come across that thread. It was some other problem, not the valves....maybe valve retainers or something like that. rudy you remember that one don't you?

* Last updated by: Rook on 1/2/2020 @ 6:51 AM *

I haven't started to work on the valve adjustment yet, I'm trying to decide if there is anything I need to do for the valve build-up. It seems like the valve gap adjustment should be straightforward except I haven't gone through the manual yet to figure out everything about pulling the cam shaft. And yes, I understand the wear comes from the valve side.

That carbon build up sure should not be there, especially on the intake. The fuel should wash off the valve when the injector sprays. If all of the others are clean like the one on the left I would suspect that valve is not closing properly. SO to confirm that pic is thru the intake with the throttle bodies off??

Either a compression or leak down test would show a valve not closing or seating, but if you say it was running fine then s/b ok. A wideband O2 sensor in the exhaust would also show the A/F ratio and if its OK its not a buggered valve.

I use BG 41K fuel system cleaner in the 911 before every oil change and it helps to minimize carbon build up

I also think you need some Hubish to explain what's going on - that would clear up the situation

Correct on your interpretation of the picture. This is the #4 cylinder with the picture taken through the air intake with the throttle bodies removed - all of the other valves are clean like the left one shown here.

So if the conclusion is that I have a valve not completely sealing, how do I narrow it down without putting everything back together to do a leak test?

Buy/borrow the leak tester and if u have a compressor you can do the test on each cylinder by pulling the plug and inserting the leak test fitting, rotate the engine so all valves s/b closed and test, good is usually ~5-6% loss (normal ring blow-by) over the test time (few min). If you have a bad valve you will know right away by the hissing sound.

Hopefully is just carbon build up and some BG 44k can clean it up some ( or some prefer the seafoam spray snake oil kit)

BTW, thanks for the advice and help.

I've got a leak tester but can't get a seal at the spark plug port - I'm getting a bit frustrated.

Here's my question/thought. I've been talking to another engine guy - not specifically a motorcycle guy. At this point it seems to him very likely that I have a valve stem oil seal leak. The characteristics of what we are seeing seems to make sense to me, but I don't know how to prove this. Also, I was originally thinking this seal could be replaced without pulling the head, but looking at the manual it appears that this seal has to be accessed from the bottom of the head.

The only other thought was an injector problem that is not spraying correctly. I talked to a local shop and his comment was simply replace them if you think you have a problem. I'm not real inclined to do this unless I can see something from testing the injector.

IF it's the valve oil seal - do I just adjust the valve clearance, try to clean some of the build-up off the top of the valve, and put everything back together and look at it again in another 15k? It seems like the oil seal leak can't be that catastrophic.

The leak test fitting should have an o-ring to seal the interface - designed so you dont have to torque it into the threads like the spark plugs to seal

I dont think its injector or the other valve would also be fouled. Valve guide makes sense but these engines are not known for guides wearing out. Another symptom of a worn valve guide would be oil consumption. Have you been adding oil on a regular basis? If you have been adding a qt every 1000 or so miles then that would indicate worn guides. If you have excessive oil consumption a bad compression test would point to worn rings, bad leak test points to valve seal. If you can put put the HD pencil cam in the spark plug hole and see excessive carbon on the piston dome as well as the valve but the other cylinders look normal or is this case less carbon then its probably time for a head teardown and valve job. But honestly I dont think it would hurt the engine to just drive it. If oil consumption suddenly goes up or power goes down you will know why and could take action then.

Hell, we may all have valves that look like this and have never looked to see. I have not had to check valves on this bike yet but on my '06 I didnt look in there.

PAIR has a clean valve.
Non-PAIR has carbon build.

Worn guide and/or cracked guild seals can be found by testing with a sustained throttle lift, especially when the engine is being pulled traveling downhill on a closed throttle. This is an even stronger vac suck with a closed throttle. Vacuum acts like E, meaning, finding the shortest path to neutralize. This is where vac is finding a leak at the guide somewhere. While on sustained lift, there is air going nowhere inside the exhaust system. When you step on the gas, a big puff of smoke blows out the exhaust pipe and then stops burning within seconds.

This [hidden smoke] is in the constant suck of it; from out of the guide at every intake stroke, remember. It too can be found in the morning upon startup. Say the valve stays open when turned off for the day. Oil flows down the valve stem, down the back of the face, drops that oil on the top of the piston dome and is about to be mixed with gas and lit off. No smoke on startup, nor smoke on lift = Not it.

What about the shell answer man and his cleaning agents in the gas? That's what hubby was saying after pulling the throttle bodies off so many times and, oh look! Stopped using costco gas and changed out to shell. Next time I pulled the bodies off for some other mod, gone was the carbon. Clean were both. That's the only change I made in the junk science of it.

Signed,
NOLTT {new old lift throttle tip}

PAIR has a clean valve.
Non-PAIR has carbon build.

I have seen that the reed valves get clogged with carbon after removing my PAIR block off plates. If the exhaust valves are right downstream from the reed valves, I can see how the exhaust valves would have a carbon build up as well. I suppose having the PAIR functioning not only burns up combustion byproducts in the exhaust system but also carbon on the exhaust valves.

Ride your 14 good and hard as often as possible and burn that carbon buildup off the valves. That's what they did in the old days before vehicles had clean air systems.

* Last updated by: Rook on 1/9/2020 @ 3:35 PM *

Well, it took pretty much 1 month to get her back on the road. Too many start and stops with only able to work on this during some evenings and weekends.

In the end, if you consider the normal 1/2 size shims I changed 4 on the intake side and 3 on the exhaust side. But if you consider 1/4 size shims, I changed 6 on the intake side and 7 on the exhaust side. Once you have it all apart and you play mix and match with the shims, it's not too difficult to get everything pretty well matched.

I soaked and cleaned the top of the intake valve that had build up - not perfect, but better than when we started. Pulled the injectors and ran cleaner through them. New plugs and removed the PAIR valve.

Everything sounds great, pulls as good if not better, and feels smooth.

Thanks for the all the input - now time to just RIDE!
http://www.zx14ninjaforum.com/userfiles/show101/20200206_140403.jpg

Glad you got it cleaned up and put back together but did you ever determine what was causing the carbon build up on the valve??

No real evidence on the buildup originates. I never got a good leakdown test to run. I bought a set-up with the oring on the plug adapter but I could not get it to seal. It makes no sense that there was anything catastrophically wrong since the bike was running fine before I started this maintenance.

In the end, it should be 1 of 2 things - valve stem seal or injector. It looked to me in the manual that the head has to be pulled to change the valve stem seal and there was no way I was willing to do that without hard evidence.

So I cleaned the injectors and decided to start running Techron every few tank fill-ups. I'll look at the valve in another 15k and we'll see.

Maybe a few more redline shifts this oil change, then at the change out send a sample to Blackstone labs to get the analysis of what crap is or isn't in the oil.

Glad it worked out and you learned a lot about your beast

Thanks for the info.

Hopefully you won't have any issues next valve check.