Weird valve clearance problem help

daveo wrote: Per Larry C: The potential for that particular tappet to be a little noisy exists because the lash would be wider than design as the lobe comes onto the opening ramp.

How does one compensate for this situation, as I have a noisy tappet on #1 or #2, but haven't isolated it to the exact location yet? The last check, all measurements were within spec. so I covered it back up, and am tolerating the noise for now.

Noisy tappets are in fact exhaust leaks every time. One cannot hear the difference in an engine with .05mm clearance vs one with .25mm.

So I recently checked my clearance on the 900 and wound up living with .003 intake and between .004 and .006 on the exhaust. Should I shoot a little higher on the intake with say .004 or .005? Any ideas. It starts very easy and rides smoother now.

RonKZ650
Noisy tappets are in fact exhaust leaks every time.

Please elaborate...are you refering to leaks where an exhaust pipe seals to the head, or something else?

daveo wrote: RonKZ650
Noisy tappets are in fact exhaust leaks every time.

Please elaborate...are you refering to leaks where an exhaust pipe seals to the head, or something else?

Exactly, the leak is right at the head to pipe junction, makes a tick that sounds like valve ticking. A common problem.

I'm a little confused now. I understand what you are saying about the odd clearance measurement, but did you mean I should move the lobe around until I find the min clearance rather than max? Wouldn't I want to shim based on the least clearance which is 0mm at the lobe perpendicular to the bucket?

So say the problem valve is shimmed with a 2.60mm shim. Based on my measurements which 0mm clearance at perpendicular and .08mm at 30degrees from perpendicular either side. Which do I shim for? 0(min) clearance or .08 (max)?[/quote]

You are looking for the max clearance. I am normaly able to find that by positioning the lobe directly opposite the bucket. If I need to move the lobe plus or min. a bit, that's okey. Again, you are looking for the max clearance.

The way Keith told me to do it was to not worry about the seemingly tight clearance wherever it may be as you turn the engine. Just decide what clearance or clearance range you are shooting for. Most guys shoot for .10-.15mm, but it's not critical, so you can be more precise and shoot for either one or the other if more precise is wanted. So for all intents and purposes a down and dirty valve clearance check can be done by simply turning the engine over slowly with your 17mm socket on the right end of the crank while constantly trying to insert a .10mm feeler, if it fits, try a .20mm feeler throughout the whole rotation of the cam. If .10 fits and .20 does not fit, you can call your clearance in spec somewhere between those two readings. Who cares if the reading is actually .11mm, .12mm, .19mm?? Not critical. To be closer decide what spec you want, most guys shoot for .10mm. Do the same thing, insert the .10 as you rotate the engine, if it goes try a .15mm, if it doesn't go you are good to go. Repeat on all 8 valves. Takes 2 minutes to check all 8 clearances and you only need a couple feelers.
Now this is Keiths way and some guys thought Keith was lazy :laugh: So Larry is a great mechanic and says otherwise is probably better yet, but it is not that critical. Most all blame on valve clearance issues is not going to be rectified by resetting clearances unless they are really at zero all the way around.

www.kzrider.com/forum/2-engine/577365-z1900-training-video

Look at the situation at hand here and use some common sense....

The lash was ZERO when the lobe was directly away from the bucket. Stop and think...what's going on in the cylinder at that point in time....

What stroke are you on?

RonKZ650 wrote: I grew up with Tim Pestotnik, who was called "the motorcycle man" and was a factory Kawasaki race mechanic for a while. Tim was killed a few years ago out in CA in a motorcycle accident, but none of this matters. He said pretty much opposite of Larry, and that was to check clearance as you slowly rotate the engine and take the point of max clearance as your spec, spin your engine with the 17mm nut, constantly check clearance on a valve and if at any point you get the .10-.15mm feeler to fit and the larger feelers do not fit, you are set. Tim said most engines were set too loose due to doing the other way. Whether this way is correct or the other which would give much more clearance in some engines is debatable, but I think it's 6 one way, half a dozen the other and doesn't make $0.02 worth of difference.

The problem with your friend's method is that it doesn't take the zero lash situation reported here into account. Zero lash at that point is not a good thing even if it has correct lash 20 degrees later. You want lash clearance through the entire compression stroke. You ABSOLUTELY want it when the lobe is straight opposite the bucket.

This particular situation is a perfect example of why performing lash measurements using your departed friends method is not the correct way. In some situations you would be OK with it but it's not a one shoe fits all solution. No disrespect to your friend intended.

Also, where the point of max lash occurs can affect the noise situation [racers don't care if the valves tick at idle].

Believe whatever you want. Set them using the method you feel is proper. Just make sure you stop and realize how the engine actually functions and take it's dynamic functions into consideration.

LarryC wrote:

RonKZ650 wrote: I grew up with Tim Pestotnik, who was called "the motorcycle man" and was a factory Kawasaki race mechanic for a while. Tim was killed a few years ago out in CA in a motorcycle accident, but none of this matters. He said pretty much opposite of Larry, and that was to check clearance as you slowly rotate the engine and take the point of max clearance as your spec, spin your engine with the 17mm nut, constantly check clearance on a valve and if at any point you get the .10-.15mm feeler to fit and the larger feelers do not fit, you are set. Tim said most engines were set too loose due to doing the other way. Whether this way is correct or the other which would give much more clearance in some engines is debatable, but I think it's 6 one way, half a dozen the other and doesn't make $0.02 worth of difference.

The problem with your friend's method is that it doesn't take the zero lash situation reported here into account. Zero lash at that point is not a good thing even if it has correct lash 20 degrees later. You want lash clearance through the entire compression stroke. You ABSOLUTELY want it when the lobe is straight opposite the bucket.

Also, where the point of max lash occurs can affect the noise situation [racers don't care if the valves tick at idle].

Believe whatever you want. Set them using the method you feel is proper. Just make sure you stop and realize how the engine actually functions and take it's dynamic functions into consideration.

Ok, yes this was my concern about setting it at most clearance. It still didn't take into account my closed lash. I think I'm going to split the difference on the opinions here. I'm thinking I'm going to try to shim down to a 250 from a 260 shim, making my clearance (hopefully) around the .10mm mark and since my clearance at 30 degrees is currently at .08mm it would make this .18mm. Making my range .10mm at lope facing exactly 180 away from the bucket, and .18mm at 30 degrees. I've ordered extra shims just in case.

I'll keep you guys posted on the results!

Noisy tappets are in fact exhaust leaks every time. One cannot hear the difference in an engine with .05mm clearance vs one with .25mm.

The first sentence is flat out wrong. The second one is generally correct but depends on the particular cam lobe being questioned.

bloglos wrote:

LarryC wrote:

RonKZ650 wrote: I grew up with Tim Pestotnik, who was called "the motorcycle man" and was a factory Kawasaki race mechanic for a while. Tim was killed a few years ago out in CA in a motorcycle accident, but none of this matters. He said pretty much opposite of Larry, and that was to check clearance as you slowly rotate the engine and take the point of max clearance as your spec, spin your engine with the 17mm nut, constantly check clearance on a valve and if at any point you get the .10-.15mm feeler to fit and the larger feelers do not fit, you are set. Tim said most engines were set too loose due to doing the other way. Whether this way is correct or the other which would give much more clearance in some engines is debatable, but I think it's 6 one way, half a dozen the other and doesn't make $0.02 worth of difference.

The problem with your friend's method is that it doesn't take the zero lash situation reported here into account. Zero lash at that point is not a good thing even if it has correct lash 20 degrees later. You want lash clearance through the entire compression stroke. You ABSOLUTELY want it when the lobe is straight opposite the bucket.

Also, where the point of max lash occurs can affect the noise situation [racers don't care if the valves tick at idle].

Believe whatever you want. Set them using the method you feel is proper. Just make sure you stop and realize how the engine actually functions and take it's dynamic functions into consideration.

Ok, yes this was my concern about setting it at most clearance. It still didn't take into account my closed lash. I think I'm going to split the difference on the opinions here. I'm thinking I'm going to try to shim down to a 250 from a 260 shim, making my clearance (hopefully) around the .10mm mark and since my clearance at 30 degrees is currently at .08mm it would make this .18mm. Making my range .10mm at lope facing exactly 180 away from the bucket, and .18mm at 30 degrees. I've ordered extra shims just in case.

I'll keep you guys posted on the results!

That should work fine.