TOPIC:

On my 750, each cam sprocket has an alignment mark that you have to set parallel to the top flat surface of the head to lock it into to being at TDC. Maybe that is what it means. See if your sprockets have similar marks.

Here is what the 750 manual shows: see the two small arrows that align the cams.

Possibly! But doesn't that mean that each cam lobe will be in a slightly different position relative to the valve?

I guess I'll wait until my FSM comes in and I can read about it!

Just measure the clearance with the cam lobe facing directly (180 degs) away from the shim.
This is the only reliable and consistent method that guarantees the reading is taken on the base circle.
Use the same method for future checks to avoid spurious results.

krayneeum wrote: Possibly! But doesn't that mean that each cam lobe will be in a slightly different position relative to the valve?

I guess I'll wait until my FSM comes in and I can read about it!

Not really, you see how it works when you get the manual. One thing to keep in mind - if you decide to change shims do NOT start the task unless you have a torque wrench calibrated in INCH pounds. Without that you can easily strip the threads of the cam caps when tightening them. Also, if you change shims take a few photos of the cam sprocket positions when the engine is a TDC so you can be confident that you have things lined up properly when putting things together. Also, it doesn't hurt to put marks on the cam chain and and when it lays on each sprocket before taking apart so you know you have the correct spacing when assembling. This isn't really necessary, especially if you have done the task before, but it may help you be positive when putting things back together. Also - I recommend you do only remove one cam at a time so there's no worry about dropping the chain in the hole and be SURE to stuff rags in the cam chain tunnel before removing the cam cap bolts. Lots of folks have dropped the bolts of other stuff down into the abyss. Ed

zed1015 wrote: Just measure the clearance with the cam lobe facing directly (180 degs) away from the shim.
This is the only reliable and consistent method that guarantees the reading is taken on the base circle.
Use the same method for future checks to avoid spurious results.

If you use this method it's best to make sure you target clearances on the wide end of the allowed tolerance range. While the valve in question will be on the base circle, the adjacent valve won't. Because of this the adjacent valve will push up on the cam and skew it within the journal clearance. Bottom line is your valves won't have as much running clearance as you measure using this method.

The FSM for the KZ750-4 specifies placing the cams in a position such that TWO adjacent valves are both on the base circle at the same time, This is a more reliable method of checking valve clearance since the cam won't be skewed out of position.

Nessism wrote:

zed1015 wrote: Just measure the clearance with the cam lobe facing directly (180 degs) away from the shim.
This is the only reliable and consistent method that guarantees the reading is taken on the base circle.
Use the same method for future checks to avoid spurious results.

If you use this method it's best to make sure you target clearances on the wide end of the allowed tolerance range. While the valve in question will be on the base circle, the adjacent valve won't. Because of this the adjacent valve will push up on the cam and skew it within the journal clearance. Bottom line is your valves won't have as much running clearance as you measure using this method.

The FSM for the KZ750-4 specifies placing the cams in a position such that TWO adjacent valves are both on the base circle at the same time, This is a more reliable method of checking valve clearance since the cam won't be skewed out of position.

The 180 degree method is the most consistent and the difference in readings is negligible.
Any valves with the clearance reading at the lower end of the range should have it's shim changed at the time of checking to put the clearance in the middle to upper range and anyone leaving a valve with a low clearance after servicing is asking for trouble.
As long as the service intervals are adhered to there will be no problems with either method .

zed1015 wrote: The 180 degree method is the most consistent and the difference in readings is negligible.
Any valves with the clearance reading at the lower end of the range should have it's shim changed at the time of checking to put the clearance in the middle to upper range and anyone leaving a valve with a low clearance after servicing is asking for trouble.
As long as the service intervals are adhered to there will be no problems with either method .

Skewing the cam within the journal clearance IS REAL, and will affect your measurements. If you want to disregard this then fine, but I'd rather follow the specified procedure. One advantage of the factory Kawasaki method is you don't need to turn the engine as much since the valves are adjusted in pairs; since both adjacent valves are on the base circle at the same time you can check the lash without moving the engine.

Suzuki specifies the same method as Kawasaki, and I've measured my old GS1000 using both methods and found the difference to be real. On a number of valves the FSM procedure suggested that a thinner shim was needed, but the pointing the cam away from the valve method did not.

One interesting difference between the KZ and GS engines is that kawasaki specifies a good bit more valve lash than Suzuki. The minimum spec for Kawasaki is .08 mm but that's the max for Suzuki. Frankly, I suspect the pointing the cam away from the valve method is good enough since there is so much clearance to begin with. This discussion is splitting hairs somewhat. If you want to split them though, you need look no further than the factory specified method.

The cam bearings will wear thus telegraphing the clearance into the reading. When the two cam lobes are both pointing away from each other you will get a more accurate reading because the cam will be pushed to the top bearings by the other valves. Plus, I was taught, setting the valve lash this way will affect valve timing, maybe not much but it does. Being able to check two valves is also a bonus.
Steve

I'll stick with the 180 degree method thanks !
It's served me well for the past 40 years as a motor cycle mechanic and hasn't done any of my many race winning engines any harm.
If my Orient Express Z900 Turbo Drag bike ( currently producing more power and better times than ever in it's history ) fails due to tight valve clearances i'll be the first to let everyone know

Nessism wrote:

zed1015 wrote: The 180 degree method is the most consistent and the difference in readings is negligible.
Any valves with the clearance reading at the lower end of the range should have it's shim changed at the time of checking to put the clearance in the middle to upper range and anyone leaving a valve with a low clearance after servicing is asking for trouble.
As long as the service intervals are adhered to there will be no problems with either method .

Skewing the cam within the journal clearance IS REAL, and will affect your measurements. ///Suzuki specifies the same method as Kawasaki, and I've measured my old GS1000 using both methods and found the difference to be real. On a number of valves the FSM procedure suggested that a thinner shim was needed, but the pointing the cam away from the valve method did not.

+1 I thought that the correct procedure was always to point the valve directly away from the lifter.

On mine, when the engine is aligned to TDC there is some valve pressure from a cam lobe. The valve timing shows some "overlap" at TDC which agrees with this. So, at TDC, the clearance reading would be wrong on those.

NOTE: On mine, you can see some fairly large (002 - 003") variations in clearance readings if the cam chain is allowed to loosen up. So turn the crankshaft in one direction only and don't reverse or the chain can slack. The pressure from the "off side" valve will raise the camshaft and change the clearance. Surprising how much "clearance" is normal in the cam journals. I used plastigauge to check mine and they were all nominal but that still leaves enough slop for reading variation from the chain loosening up.

You don't need to remove the cams to change the shims, you use the special tool to push the follower down and then you pull the shim out with a magnet.

Oh sorry on this engine you do need to pull the cams because the shims are under the follower, my bad!

zed1015 wrote:

Nessism wrote:

zed1015 wrote: Just measure the clearance with the cam lobe facing directly (180 degs) away from the shim.
This is the only reliable and consistent method that guarantees the reading is taken on the base circle.
Use the same method for future checks to avoid spurious results.

If you use this method it's best to make sure you target clearances on the wide end of the allowed tolerance range. While the valve in question will be on the base circle, the adjacent valve won't. Because of this the adjacent valve will push up on the cam and skew it within the journal clearance. Bottom line is your valves won't have as much running clearance as you measure using this method.

The FSM for the KZ750-4 specifies placing the cams in a position such that TWO adjacent valves are both on the base circle at the same time, This is a more reliable method of checking valve clearance since the cam won't be skewed out of position.

The 180 degree method is the most consistent and the difference in readings is negligible.
Any valves with the clearance reading at the lower end of the range should have it's shim changed at the time of checking to put the clearance in the middle to upper range and anyone leaving a valve with a low clearance after servicing is asking for trouble.
As long as the service intervals are adhered to there will be no problems with either method .

100% Agree. Point the lobe away and set the clearance as close as you can get to max loose spec.