Z1 - no marks on camshaft for setting valve lash?

Got my topend back together... The original '74 head on my bike was shot. Broken fin, small cracks from some bonehead trying to pry it off in the wrong spots and split valve in #2.
Got a spare '73 head, cams, pistons and cylinders off ebay. Had the newly acquired cylinders honed, valve job done, new oil seals etc.

After ringing the pistons, putting the cylinders and the head back on I set the timing - the cams have the arrow and 28th mark - no problem there. Everything turns freely.
Then I went on to set valve clearance, but there's no alignment marks on the cam sprockets... Anyone know what's going on?

I know I can just measure lash with the lobe 180 degrees away from the tappet so I don't really need the marks, I just can't figure out if I should be worried about the cams being right for the head (that's what you get for ordering off ebay I guess). Anyone got any ideas?

Maybe try meauring and comparing with a micrometer?
Scott

77kz650,
I can do some crude measurements tomorrow using my vernier caliper, but that's about it. Don't own a micrometer unfortunately.

It never occurred to me that the cams might actually be different until I started thinking about it tonight. Like I said, everything turns freely so I'm not TOO worried, it just has me puzzled. I'm halfway done setting valve lash, just need some thinner shims. I was hoping someone would chime in and reassure me there's 900 cams out there without the alignment marks on them. I know it's kinda late and I'm on the westcoast, so maybe I'll have to wait until tomorrow.

I could swap out the cams and be done with it, but I'm interested in the exact cause now that I ran into this. Plus I broke three (3) cam cap bolts while torquing the cams down :pinch:. Thank god for left handed drill bits. Maybe the PO overtorqued his bolts? so I ended up taking them all out and swapping them for the ones off my old head.

Dutch if you have the:

^
|
28 on the intake cam sprocket and the:

>

on the exhaust cam sprocket,

I would be surprised if you don't have the marks you line up horizontally to set the valve lash. Please refer to the article:

kzrider.com/content/view/36/11/

The marks do not stand out all that much and are just lines. On the intake cam sprocket, the one side is very short due to little material in that area. If you can't find the marks, I suggest you get a set of new cams or cam sprockets. Drop me a note if you need help with this.

I thought you could just turn the motor, and measure the maximum clearance whenever it occurs?

Ltdrider, I can set valve clearance without the lines I'm just puzzled. Maybe they fell down the camchain opening :laugh: ?

WG, that's what's weird, the 28 & arrow mark are there, the lines are not. I have the cams off my '74 head, should I just swap them out?

Swapping cams should NOT be a problem. But just for fun.. look at the sprockets on the other set of cams. See if the mark is clearer on them. I'm wondering if someone switched cams at some point ( after market ) of cam sprocket?:dry:

The marks on the other set of cams are there... Maybe someone did swap cams or sprockets on the head I bought. I just measured the lobe height (don't know if that is the correct term) and it is the same as far as I can tell with a vernier caliper. Apart from the sprockets the cams LOOK identical.

Never saw any without the lines for valve lash a

Never saw any without the lines for valve lash adjustment. I have about 5 or 6 sets of cams sitting around (stock 900 type) and sure would be hard pressed to see any difference in any of them. I have at least one set of 74 cams and I think they all have the lines. Hmmm... You don't really need the lines to set valve lash but it makes your measurements as consistant as they can be I guess.

Thanks for the advice all. I'll throw in my other set of cams. Hope I get the timing right again and I don't snap anymore cam cap bolts...

Swapped out the cams, no problems... I triple checked and although the rubber on the set I took off looks decent, there are no lines. Thanks for your help, everyone!