Head rebuilding z900

Hi, I am new member of this forum. I own Kawasaki z900a4 from 1976.

A few days ago I take of head and cylinder to change head gasket cos it leaks. As I havent got to much experience with rebuilding I go for the book. Kawasaki service manual.
But when I removed valve cover I wanted to check how my camshafts was set and I saw a few problems.
1. Signs on crankshaft are not the same as in the manual.

Ok, I set crankshaft in line with T mark, and exhaust
camshaft sign in line with head surface. Now I start to
count pins on camchain starting with first above the
sign on ex. camshaft, back to intake camshaft.

2. When I arrive to 28 sign on intake camshaft I have
counted a 30 pins on cam chain :ohmy:

Manual said count 28 pins to 28 mark on intake camshaft!
Can anyone explaine this?
Is this a wrong setting or I have some aftermarket parts in my bike. I was rideing it for a whole last year without
any problems. Or I havent notice them.
Please help!

It's been a while, but I think the correct procedure is:

1) On mine, you set the intake camshaft in first.

2) make sure the chain slack is pulled out TIGHT to the bottom crankshaft gear and when you check for the cam alignment to the top surface of the head.

3) then install the exhaust cam, do the "count link thing" again. I think if the slck in the chain is taught, you should have the correct link count.

The picture above in the middle shows that cam is not level as it should be. Maybe the chain needs to be shifted on the gear wheel.

Yes I know the procedure, but this pictures show how my camshafts was set before I removed head. And it was working fine. So I dont know can I set it again like this after rebuilding or I must working by the manual.
It seems to me that this was a wrong setup but I dont know how this wasnt produce any problem with bike engine.

OldSchoolHr wrote:

Yes I know the procedure, but this pictures show how my camshafts was set before I removed head. And it was working fine. So I dont know can I set it again like this after rebuilding or I must working by the manual.
It seems to me that this was a wrong setup but I dont know how this wasnt produce any problem with bike engine.

The only explanation I know of is that these are aftermarket cams which don't time the same as stock cams.

If they run well like they are, I would throughly document exactly how they are set right now and keep that with the manual so you will know how to put them back together.

bountyhunter wrote:

If they run well like they are, I would throughly document exactly how they are set right now and keep that with the manual so you will know how to put them back together.

Yes but how do I know is this setting that I had before right?
Is it possible that distance between cams be 2 pins
more and that engine is still running without any damage?
Maybe in that case engine works but is lazy!? How will I know?

To set the cam chain timing, do the following:

Rotate the engine to TDC for #4 cylinder. To do this, align the timing mark on the engine cases with the T mark on the mechanical timing advance. To verify, put your finger or a pencil in the #4 plug hole and see if you can feel the piston crown.

Remove the cam chain idler assembly AND the tensioner. Install the INTAKE camshaft and tugging, pulling, yanking, and wiggling the cam chain in front to ensure it isn't bunched up. There is an ARROW on the cam chain sprocket like this: >
This arrow should point to the gasket mating surface of the cylinder head (horizontal point). IF you fail to unkink the chain (IT WILL BE KINKED DOWN ON THE CRANKSHAFT), you will not set the timing correctly. Pull that chain up TIGHT around the cam chain sprocket and set the > to the gasket line on the head.

Then, start counting the pins on the chain. The first pin to be counted is the one just above the arrow. Mark the 28th pin.

Put your exhaust cam in place with the 28T mark pointing up at the 28th pin.

Reinstall your idler assembly and tensioner and turn the engine over using the large nut on the end of the crankshaft under the points cover. Turn the engine over a couple times and re-verify the number of links... you may have to remove the idler assembly again to do this.

If you are still off by a couple of pins, count the number of teeth on your cam sprockets. It could be you have the sprockets or cams from a MKII engine which uses a 124 link cam chain rather than the normal 122 link chain used on most all the other 903/1015cc KZ engines. The sprockets ARE DIFFERENT in that they have different number of teeth as the MK II crank cam chain sprocket has a different number of teeth.

Wiredgeorge you said that I put INTAKE camshaft first, did you infact mean EXHAUST camshaft?
When I was removing my head off I did just you wrote.
I aligne T mark and check TDC on #4, aligne marks on both camshafts and I still dont uderstand why there was a 30 pins between my camshafts?
Maybe I realy got larger sprockets on my cams cos diference
in timing is 2 pins.
My camshafts are in machine shop together with head so I cant check how many teeth sprockets have but from picture
above I caunt 16 teeth on half of sprocket so I asume that
they are 32 teeth sprockets.
Can you tell me how many teeth has original kz900 camshaft sprocket?

Toni,

First, I think you are right. WiredGeorge meant to say to install the Exhaust cam first. That's how I've always done it (unless the 900 is done differntly than the 1015).

As for your cam sprockets, I think you DO have MKII sprockets. According to this site: kzzone.com/sprockets.html , the standard KZ900/1000 cam sprocket has 30 teeth. The MKII sprocket has 32. So it appears that you have a non-stock configuration. You probably have an MKII crank too.

Ok, I have one more question about valve clearance.
Head from my z900 is in machine shop for total rebuilding.
I want to know what valve clearance I should set up for exhaust valves and for intake valves.
Mesures are in mm.
Manual said that valve clearance should be from 0,05 to 0,10 and my mechanic said that he would set clearance 0,10 for intake valves and 0,15 for exhaust valves!?
What do you think about that?
What do I get with that clearance (in. 0,1 / ex. 0,15) vs for example (in. 0,06 / ex. 0,08)?
Please, help

OldSchoolHr wrote:

Ok, I have one more question about valve clearance.
Head from my z900 is in machine shop for total rebuilding.
I want to know what valve clearance I should set up for exhaust valves and for intake valves.
Mesures are in mm.
Manual said that valve clearance should be from 0,05 to 0,10 and my mechanic said that he would set clearance 0,1 for intake valves and 0,15 for exhaust valves!?
What do you think about that?
What do I get with that clearance (in. 0,1 / ex. 0,15) vs for example (in. 0,06 / ex. 0,08)?
Please, help

My KZ750 uses the same clearance (0.05 -0.1mm) which is about .002" to .004".

Your mechanic is recommending .004" - .006" to get a little "headroom" to make sure the valves don't get tight after all the parts seat, since a tight valve will not only run poorly it can burn the valve seat and destroy the head. I tend to agree with that precaution. I set mine to .003" - .005" after the rebuild.

There is a very slight reduction in total cam lobe "lift" during the cycle if the valve clearance is wider, but I doubt you could notice an extra thousandth or two unless you have a dyno to test it on. Even then, maybe not.

Ok I have finished my cylinder/head rebuilding. It is all
OK for now. I started engine without exhaust just to test is it working. And yes its alive! Aleluja!!!
Tomorrow I will clean and put on exhaust and run engine to working temp. After that I will tighten head again.

And I did cam timing by the book (28 pins between cams )
I dont know why previous timing was set on 30 pins between mark on ex. cam and 28 mark on in. cam.
I think I will see diferences between these 2 settings when I gone for a ride tomorrow.
I think that 28pin set is correct one and cams now are in better position than before.

All pics of reasembling and asembling you can see here
s249.photobucket.com/albums/gg222/limit_...%20photos/?start=all