Reassembly- Cam Timing

So as some of you know, I am in the process of rebuilding my pops KZ900.

Good news is is that I got all the valve clearences all figured out (THANKS TO YOU ALL ), and I got the whole head together and on, torqued down and good to go. Now, my question is..

The cams. What is the first thing that I should go about when putting the cams back in. Right now, I have cylinder #1 at TDC ready to be "sparked" (my term for TDC on the power stroke). Anyways, is there any easy way to do this? I noticed there is two straight line marks on the cam gear (I first noticed those while reading the article on valve shimming), and I also noticed there is a arrow facing upward on the gear as well. One last thing I did notice is there are two "beige" dots on the came CHAIN. I did not measure the length in between them, but if I were to lay the chain flat on a bench, I would say they are about 6 inches apart. Do any/all of these markings have a relation to each other, all in connection with the motor (as in what position the pistons are at)? I tried searching on here for cam timing, but not many specific results came up. Thanks.

P.S. Sorry for all these questions, but you guys do know your stuff, and that's what I'm here for

Post edited by: cuddies, at: 2007/05/21 13:14

Cuddies...You have to read in the manual,Bud...how to set the timing chain up from the start.
Those arrows that You see(on the cams),are there for setting the cams in relation to T.D.C.(which You say You already have set)...the marks on the chain are reference marks,but for now...forget those,because unless You have the chain set on the cams exactly where they were from factory,You will be making a new mark.I'm referring to You have to do a "28" chain-pin count from the exhaust cam,over to the intake came,and once the INTAKE cam is sitting in the head with IT'S arrow(marker) facing perfectly horizontal with the head(same applies to the exhaust cam,with that arrow).
Now where You START that pin count will be the very next pin above that arrow on the exhaust cam,BUT...You really SHOULD have that info there with You,so You can double check(triple check even)as You go,so You KNOW that You're not a link out when it's all said and done.

Do You have a manual?

Check out the thread on manuals to download,here.I think there's one for Your bike.
I might even have that info here somewhere on the computer...

Also...make SURE You're bike is NOT on the kickstand during this procedure,because the cam chain won't grab onto the crank properly...have the bike vertical when doing this...very important!

And yes...the manual for Your bike IS in that thread...first one actually.Download it,and have it handy.Print out the cam timing info and have it with You at the bike...read it and understand it before You continue,Bud.

Everyone sing with me. . .

Cuddles' making progress, cuddles' making progress. . .

:laugh:

Anyway, once you get the cams and crank and all lined up. . .and the cam chain adjuster adjusted. . .

have no spark plugs in it. . .

use a wrench on the crankshaft nut (17mm) points side of the crank. . .

to rotate the engine really slowly through about four revolutions clockwise. . .

If it binds at all . . . STOP.

If it binds at all . . . Cam-valve / Crank-piston are meeting by accident.

If it binds at all . . . recheck TDC and cam sprocket coordination.


:side:

Guys, thanks for the tips.

As for the manual, I went to the thread, downloaded the file. When it was done downloading to my desktop, I go to open it, and it opends 6 files. I go to open those files, and it says it's "locked". So I uninstalled it, figuring there might have been an error, and reinstalled it, and it did it again.

As for the kickstand, I have it on that center stand thing, not the actual kickstand. I'm not sure what it's techinically called, but its the one the is under the bike that flips down. So I have that under control there.


I am going to go try and download that manual again, I guess I really need it.

But, let me make sure I have this right from your post. (these are my steps below: )

1. Set piston 1 at TDC (which I already have)

2. Set the INTAKE cam arrow facing exactly horizontal with the head (does the arrow face towards the front of the bike, or towards the carbs?)

3. MARK the chain pin exactly lined up with the arrow

4. Count 28 pins, and the 28th pin SHOULD be aligned with the EXHAUST cam arrow.

5. Double, Triple check.

6. Have fun:) LOL

:ohmy: no no, it's the exaust cam that has the mark that goes horizonal to the head! The mark your looking for is on the exaust cam sprocket tooth, on the right side, can't see it with the chain on (on mine anyway). The arrow on the intake cam is for the 28th chain pin, if you look close at the rubber by the arrow it should have a "28" molded in. Start counting from the pin just above the mark on the exaust sprocket.

I didn't want to say anything, because I have a 650, and thought maybe it was different, but TWO folks are telling you what I will repeat. Since you have it in theory, but incorrect in reality.

cuddies wrote:

. . . I have it on that center stand thing, not the actual kickstand. I'm not sure what it's techinically called, but its the one the is under the bike that flips down. So I have that under control there.

1. Set piston 1 at TDC (which I already have)

2. Set the INTAKE cam arrow facing exactly horizontal with the head (does the arrow face towards the front of the bike, or towards the carbs?)

3. MARK the chain pin exactly lined up with the arrow

4. Count 28 pins, and the 28th pin SHOULD be aligned with the EXHAUST cam arrow.

It's called a centerstand. Got that right. Partial credit.

Sandy wrote:

Cuddies...You have to read in the manual,Bud...how to set the timing chain up from the start.
Those arrows that You see(on the cams),are there for setting the cams in relation to T.D.C.(which You say You already have set) . . . You have to do a "28" chain-pin count from the exhaust cam,over to the intake came,and once the INTAKE cam is sitting in the head with IT'S arrow(marker) facing perfectly horizontal with the head(same applies to the exhaust cam,with that arrow).
Now where You START that pin count will be the very next pin above that arrow on the exhaust cam

Z1R rider wrote:

:ohmy: no no, it's the exaust cam that has the mark that goes horizonal to the head! The mark your looking for is on the exaust cam sprocket tooth, on the right side, can't see it with the chain on (on mine anyway). The arrow on the intake cam is for the 28th chain pin, if you look close at the rubber by the arrow it should have a "28" molded in. Start counting from the pin just above the mark on the exaust sprocket.

So what they are saying is apparently:

Set the EXHAUST cam FIRST. ARROW to front.

Set chain. First pin ABOVE arrow, is number one. Count 27 more, should be 28, and apparently INTAKE arrow lines up with that pin somehow. Until you place the overhead guide in place, I think the intake cam is going to look off in terms of arrow pointing parallel to head.

Advice: LOOK AT THE MANUAL. LOOK AT PRETTY PICTURES.

:laugh:

Hold on,hold on...

Both cam SPROCKETS have the arrows,and BOTH arrows MUST line up,flush to the head.The exhaust arrow will be facing forward,to the front wheel,and the intake arrow will be facing the rear wheel.
The intake sprocket will be clearly marked with "28" on the black plastic area(or what ever material it is)
Look at the attached pics and You'll see.
Where You see the "28"...THAT is where the 28th pin should be,on the sprocket.
When You have this all set up(properly) You'll notice the cams are laying exactly opposite of each other.I can't remember for sure,but I THINK the lobes for 1 and 4 will be laying flat,and the exhaust will be facing forward,like the arrow on the sprocket.Either way...as long as You ARE at TDC on 1 and 4,and You get the arrows lined up correctly,and You have the 28 pin count bang on,and the intake arrow is laying flush to the head surface as well,and because the sprockets will only bolt on one way...You're good to go.

And like mentioned...remove all plugs and when You're turning the engine over...do it sloowwwwwwwly.And don't turn it over backwards...only forwards,because of slack in the chain in certain areas.

The sprockets in the pic are set up the correct way,for You to see,except they would be upside down,because obviously,they're not mounted on any cams.
Any confusion,just remember that Your exhaust cam has the splines on it,for the tach-drive,and the intake cam does not.

a pic of the arrow...

Oh AND...do Your pin count BEFORE You mount the top idler tower,so You can CLEARLY see all links and pins,cause You'll go squirrley if You don't,lol.:silly:
But...do NOT turn that engine over until You have that top idler bolted down,and EVERYTHING bolted down.
And as You're tightening down the bolts FOR the top idler...if it feels like You're putting too much pressure on the chain,then stop,because the chain may not be hooked onto the crank,properly,so You'll have to start over until it is.
You will have the cam chain adjuster OUT for this procedure,btw,but make sure You put it back on before turning the engine over,and make sure it's adjusted properly,once You get everything else figured out.
Before You do anything,actually...make SURE that the chain IS properly attached to the crank...You'll know when it is,because when You tug the chain from Your left hand to Your right hand,it will be solid,and won't slip from either side.
I hope this all made sense...:whistle:

Get that manual issue figured out too.:laugh:

:blush: I've had these cams out lots of times over the yaers and never noticed that the intake sprocket was marked with a poniter also, always lined up the exaust, counted pins, and buttoned it up. Learn something every day, thanks Sandy