Both 1 and 4 will be at TDC but they won't both be at the end of the same stroke. You can tell my looking at the cam lobes as to which one you have at TDC at the end of the compression stroke. All the lobes for the valves you need to measure should be pointing up (not pushing on a valve). So, you usually put #1 at TDC at the end of the compression stroke first, measure all the valves in the top pic, then turn it over another turn to get #4 at TDC at the end of its compression stroke so you can measure all the valves in the bottom pic.

 

Here's a picture of when I did mine and this would be when #1 is at TDC at the end of the compression stroke:

See how the lobes are up on all the valves it tells you to measure in the first pic? I had already taken all the measurements and was in the process of pulling the cams to change the shims out.

 

my next project.....:headbang:

 

hi trackdayhero,

thanks for the brilliant tips.

just want your confirmation, let's say,when the #1 at TDC, the measurement should be taken when the cam lobes of both IN & EX at the opposite direction...Am I correct?


also,

when you rotate the timing to get #4 at TDC, Does the mark 1/4 still align to crankcase mating surface? or mark 2/3 in align?

Thank you.

 

Yes, when #1 is at TDC at the end of its compression stroke the #1 IN and EX lobes will be pointing up and away from each other and yes, when you rotate the crank another turn you put the 1/4 back on the mark and that should put #4 at TDC at the end of its compression stroke. Then #4's IN and EX lobes should be pointing up and away from each other. Remember this is a 4-stroke so it takes 2 full turns of the crank to complete a full cycle. When #1 is on its compression stroke, #4 is on its exhaust stroke. They are 1 full turn of the crank apart.

So you want to get #1 at TDC at the end of its compression stroke. That's where you take the first set of measurements. Then you put #4 at TDC at the end of its compression stroke and you take the second set of measurements according to that second picture you posted. But technically you probably don't have to actually measure at exactly those spots. The key is to have the lobe pointing away from the valve when you measure (so you are measuring the largest gap).

 

Actually what I said was wrong as far as 1 "or" 4 at TDC when that mark is lined up. Actually both 1 AND 4 will be at TDC but they will be at the end of a different stroke as I mentioned. I edited my other posts to try to be less confusing. One of the two will be at the end of the compression stroke and the other will be at the end of the exhaust stroke. But, you have to turn the crank another turn to reverse which one is at the end of the compression stroke and which will be at the end of the exhaust stroke. Sorry for the confusion!

 

I am a bit confused.

are we looking at the cam lobe pointing up to get TDC for #4 or a mark of crankshaft mark 1,4? to get the measurement valve clearance of cylinder #4.

as you said, to get #4, we have to rotate full cycle and place the mark 1,4 align the crankcase mating surface.

thanks

 

It's a 1 + 1 kind of a deal. You have to have the crankshaft mark to know you have #1 and #4 @ Top Dead Center. As one will be on the compression stroke and the other will be on the exhaust stroke, you have to identify which is which by the position of the cam lobes.

If the low part of each cam is acting on the valves, that cylinder is on the compression stroke. (lobes not pointing at the valve stems).

The other cylinder of that pair will come to it's compression stroke 360° of crankshaft rotation later. At that time, both #1 and #4 will again be at Top Dead Center... except the opposite cylinder will be on the compression stroke.

 

What year bike is this so I can look in your service manual?

 

Your pictures look just like what I see in the 636 manual for 04/05. I'm not exactly sure what you are confused about. You might want to read through all of my posts again as I edited them to try to be less confusing. There is another indicator on the outside of the cam sprockets themselves and they are marked in that drawing that you posted in your first message. When #1 is at TDC at the end of its compression stroke the EX and IN marks on the outside of the cam sprockets will be pointing away from each other. When #4 is at TDC at the end of its compression stroke the EX and IN marks on the end of the cam sprockets will be pointing toward each other as it shows in the drawing. I do notice that the directions in the service manual for my '08 are MUCH better than what is in the manual for this bike. You might want to download a copy of the manual for the '08 and read through the instructions and see if it fills the gaps. Things are a little different (like where the 1/4 mark is) but the principle is exactly the same.

 

Disregard looking at the '08 manual. It's almost identical to yours. Not sure why I remember it being more descriptive than it is, guess I just understood what needed to be done. But, like I said the key is that the lobe be pointing up on the valves that you are measuring. They should not be turned down to where they are pushing the valve.

 

my bike is zx6r 636 2006.
So meaning that.. For cylinder #4, the cam lobes for Both IN and EX are pointing toward each other. Is that correct? But do we still check and need to align mark 1,4 while we rotate?

 

Maybe you are confusing cam lobes with the EX/IN marks on the outside of the cam sprockets? If you are talking about the EX/IN marks on the outside of the cam sprockets then yes, when #4 is at TDC at the end of its compression stroke those EX and IN marks will be pointing toward each other and the 1/4 mark will be lined up with the mark. When #1 is at TDC at the end of its compression stroke those IN/EX marks on the sprockets will be pointing away from each other and the 1/4 marks will be lined up with the mark. The "lobes" that I am referring to are the elliptic shaped parts of the cam that actually push each valve down when they rotate.

These are lobes:

It's very hard to see the EX/IN marks on the outside of the cam sprockets on my ZX6Rs but here is what they look like on my 650 where you CAN see them:

On my ZX6Rs I had to use a mirror, and even then you can't really see them so that's why I just looked at the position of the lobes to tell which piston was at the end of its compression stroke. Here I am trying to see the marks with the mirror, very unsuccessfully:

More pics:

http://s1179.photobucket.com/user/vmdirt/library/ZX6R Valves Green?sort=3&page=1

 

Another thing that may be confusing you, and it even confuses me is there are multiple IN/EX marks on those damn sprockets as you can see in this pic:

That's why I don't even pay attention to them. I just align the 1/4 marks and look at the lobes to determine which piston is at TDC at the end of its compression stroke. When I have #1 set at TDC at the end of it's compression stroke I mark the inside of the cam sprockets with a dab of white paint as you can see in the above picture. Then when I rotate the crank another turn and line up the 1/4 mark again those marks will be pointing toward each other and I can measure the other half of the valves. I also know if I have the cams back in the correct position after I put them back in after changing out shims by putting the marks back exactly where they were before pulling them.

 

Great Thread!!!

I would like for some of the posters to show how they do the shims (Please! LOL!!). Maybe using pics, walk through the complete start to finish of doing one cylinder.

 

http://zx6r.com/mechanical-technical/31035-another-valve-clearance-thread.html

 

Thanks all for kind info, advise and perfect forum here.

I just wonder what are kinds of sign / indicators of not changing the shim?

I have my 6r 2006 and had change the slip on exhaust since long time year ago. now, I notice, the sound of exhaust is getting a bit louder than before when after I ride and the sound of engine is kind of weird. I believe it is not the valve and cct. I notice the manifold exhaust is kind of overheated.

any Idea?