TOPIC:

I have an 81 KZ550 LTD. After a rebuild to remove the two little choke flaps that came off I have a valve clearance question. After reading the info here and putting each cylinder at TDC I have one intake valve that is at .003". I can't get a .004" in there. Any need to be concerned? It was running fine before and I've run it since the build.

lhemrick wrote: I have an 81 KZ550 LTD. After a rebuild to remove the two little choke flaps that came off I have a valve clearance question. After reading the info here and putting each cylinder at TDC I have one intake valve that is at .003". I can't get a .004" in there. Any need to be concerned? It was running fine before and I've run it since the build.

If the bike ran fine before, I don't think the clearance could have been that small. I think you would have had a rough idle or stalling issues when hot.

Is the valve clearance issue on a cylinder that was missing a flap? If so, I would do a compression test and/or leak down test. Maybe there is something holding the valve open just a hair... like being slightly bent or some remnant of a flap in the valve seat.

If the compression is good (near 180 psi - ish) I guess you would just change the shim according to the shim-schedule in the manual, run it, and see how it runs. But I strongly suspect the small clearance is telling you something is wrong with that valve or seat.

lhemrick wrote: I have an 81 KZ550 LTD. After a rebuild to remove the two little choke flaps that came off I have a valve clearance question. After reading the info here and putting each cylinder at TDC I have one intake valve that is at .003". I can't get a .004" in there. Any need to be concerned? It was running fine before and I've run it since the build.

Yes, be concerned. The minimum clearance spec for intake valves is .004" so your valves may not seat when the engine is hot, and that will damage the engine. Further, be careful to position the camshaft per the factory service manual process or the measurements will be incorrect.

There wasn't anything wrong with the valve or seat. I took all the valves out and inspected them and the seats. I rotated the engine for each cylinder and set the lobes pointing opposite from each other and the "T" on the timing mark and measured. Is that not correct?

lhemrick wrote: There wasn't anything wrong with the valve or seat. I took all the valves out and inspected them and the seats. I rotated the engine for each cylinder and set the lobes pointing opposite from each other and the "T" on the timing mark and measured. Is that not correct?

The best way is with two adjacent valves need to be on the base circle at the same time, and then both checked without moving the engine. This is the method Kawasaki adopted on the later year 1000/1100 bikes because it provides the most consistent measurements.

Sorry Ihemrick!
I mis-interpreted the numbers in my head. .003" is not a drastic deviation from the minimum for intake. A 550 will probably run fine at that value most of the time. The classic valve-out-of-spec symptom you'll get on a 550 is immediately after a hard highway run, if you come to a stop, the bike will stall instead of idle. When that happens one or more of the clearances will just start to be out of spec.

I've found intake clearances down to .0025" on Kz550 engines and the motor still ran ok until a highway run.

So to answer your original question about concern, if it was my bike I would NOT be concerned unless there were other symptoms. Yes, you should probably adjust that valve, but it's not any imposing disaster, and not really abnormal. I think if you just wanted to start it up to see if the engine is ok overall, I don't see any harm in starting it as is. You can change the valve shim later, ... soon... but later.

I hope you read this before you tear anything apart.

I presume you've probably read that valve train link in my signature. It has details about measuring valve lash if you scroll about half way down. Like Nessism said, the FSM procedure is the way to do it. That link basically summarizes the procedure.

I did and I really appreciate that info. I am a little confused though about the whole "cyl #1 at tdc measure intakes 1&3" etc. As I was doing this I found sometimes a lobe would have a spring depressed and no way to measure. Was I doing something wrong?

I've posted this a number of times previously in threads now in the archives but it seems to bear repeating.  The camshaft position for valve adjustment is important because it puts two adjacent valves on the base circle at the same time, this then allows you to measure both of those valves without moving the engine. It's important to avoid having the adjacent valve to the one you are checking depressed because that pushes the camshaft upward in the journal clearance and the measurement will be larger than it truly is.

A simple way to position the cams involves...

1) Aim #1 Exhaust cam lobe forward, level with the gasket surface, and then measure #1E & #2E
2) Aim #4 Exhaust cam lobe forward, level with the gasket surface, and then measure #3E & #4E

3) Aim #1 Intake cam lobe straight up, 90* to the gasket surface, and then measure #1I & #2I
4) Aim #4 Intake cam lobe straight up, 90* to the gasket surface, and then measure #3I & #4I

With the FSM procedure, you should be able to read the specified valves, but it's very easy to try to read the wrong one.
You can see in these photos, the lobes are not pointing directly away from the bucket, but the lobes should not be in the pressing range.

The FSM specifies TDC positions, and reading the following order.
Intake is on the left side of the images.
Cylinders are numbered top to bottom in the images.

With cyl #1 at TDC of the power stroke, measure the lash on intakes #1 and #3.
Intake 1 is pointing backward. Intake 3 is pointing up.


With cyl #2 at TDC of the power stroke, measure the lash on exhaust #2 and #4.
Exhaust 2 is pointing forward. Exhaust 4 is pointing up.


With cyl #3 at TDC of the power stroke, measure the lash on exhaust #1 and #3.
Exhaust 1 is pointing up. Exhaust 3 is pointing forward.


With cyl #4 at TDC of the power stroke, measure the lash on intakes #2 and #4.
Intake 2 is pointing up. Intake 4 is pointing backward.

lhemrick wrote: I have an 81 KZ550 LTD. After a rebuild to remove the two little choke flaps that came off I have a valve clearance question. After reading the info here and putting each cylinder at TDC I have one intake valve that is at .003". I can't get a .004" in there. Any need to be concerned? It was running fine before and I've run it since the build.

Not sure on the issue? You mean with the thinnest shim you can't get more than .003" clearance? That means the stem height is too high. A bent valve would give way too much clearance because it can't fully seat. What size shim do you have in the bucket with the tight clearance?