TOPIC:

Hi guys, I could use your experience inside these engines.  I'm reviving my 1974 Z1 as a retirement project (I've owned it since 1980, hasn't been ridden since late 90's).  Today I was checking valve clearances.  Removed spark plugs, removed valve cover (thanks to you guys I now know to move cover to the rear to remove instead of 20 minutes wrestling with it to find the one "sweet spot" between upper idler and the frame to remove it straight to the side).  When I turned the crankshaft (yes I used the larger 17 mm nut) to compress the first valve for the factory kawasaki tool that's been in my toolbox since the 1980's, the crank turned about a half revolution then seemed to bind up and jam.  Then I saw it -- oh crap!  I had removed the cam chain tensioner to order and replace the spring but I forgot to re install the tensioner.  After installing and setting the tensioner, the crank still rotates about a half revolution in either direction and stops.  I did not force it past those points.  Is there a simple answer/fix or will I be ordering head gaskets for when I re assemble the upper part of the engine?

Thanks,
Scotty

Is the transmission in neutral?

If so, then I guess the next step would be to check camshaft alignment. If you cannot get the crankshaft to TDC, then a peek in each cylinder to see if there is contact would be my next choice. You can get a cheap borescope / camera on fleabay.
If the chain jumped a tooth or two, it should be possible to get things lined up again without removing the head.just remove the cams and reset according to the service manual.

I think Texas is right.  When you removed the tensioner your timing chain moved.  That solid object you encountered is a piston hitting a valve.  The fix isn't all that diffficult.

Remove the top cam chain idler.  Remove the tensioner on the rear of the engine.  Remove the cam bearing caps and pull the cams off.  Re-set your ignition timing for 1/4 TDC.  Pull the cam chain taut and ensure it's on the crank sprocket by rotating the engine.  Hold it taut so that no slack is allowed.  Re-set your ignition timing for 1/4 TDC.  Re-install your exhaust cam as described in the manual.  (There is a mark on the RHS that should be parallel with the head surface.). Re-install the intake cam.  Count back 28 links on your cam chain and put it on the intake cam at the mark on the RHS.  Re-install your cam bearing caps as described in the manual.  Use a torque wrench to get the correct torque value and be careful as you tighten the bolts so that you don't strip one out.  Re-install the top cam chain idler.  Re-install the rear tensioner.  Very gently attempt to rotate the crankshaft clockwise from the 17 mm nut to see if it will rotate at least one complete turn.  If you encounter resistance then you are either off the crank sprocket or you have slack that allowed your timing to go off again.  If the crank rotates correctly then double check your timing marks again with the ignition mark at TDC.  You are now done.

 

Thank you.  That is the relatively easy solution I was hoping for.  I only have access to the bike on weekends (it's at my friend's garage/shop), so I'll try it next Sunday and let you guys know how it turns out. Hopefully I'll be riding it this summer.
 

Slack in the cam chain sometimes bunches up on the crank sprocket, causing binding.

You need to make sure the chain isn't hanging up anywhere, then check timing of the cams.  It's possible that the cam chain jumped some teeth on the cam sprockets.  A relatively easy fix, just as long as you are careful to never force the engine to rotate.  And to that ends, after swapping out shims and adjusting cam timing, be sure to turn the engine over using a wrench several times to make sure you don't have any interference anywhere.

I like all of the suggested repairs above. I would do one more thing personally if I was in this situation. When you have the cams out of the engine hold the cam chain so it will rotate with the crank. Rotate each cylinder one of the time down to bottom dead center. Use a compression tester and make an adapter to shop air. Turn down your shop air to around 50 or 60 psi and pressurize each cylinder. Listen at the exhaust, the carburetor intake, and at the crank case breather. If you hear any air escaping through the exhaust or carbs, you have bent a valve. The head will have to come off to fix. It may save you a hole in a piston if the valve is bent.

Excess clearance on one valve is also an indication of a bent valve. 
Steve

Mikaw, while my cams are off, I'll do the compression test as you described.  Right now the carbs are off while I clean them, and the exhaust header is off for repair or more likely a delkevic so it should be easy to hear any leaks.  I'd better get an early start Sunday, looks like I'll have a busy day!
Thanks,
Scotty

Update:
Removed cams, set crank at T 1-4, installed cams timed according to kawasaki repair manual, torqued cam cap bolts to 104 inch-lbs.  Engine now rotates free, timing stays correct. Rotated it 10 or 11 revolutions just to be sure, (also to celebrate a little).  I forgot how tiny the arrow on the exhaust cam sprocket is!  While cams were out I covered cam journals, bearings and lobes with engine assembly lube, extra lubrication can't hurt at start up. Clearances are now all at  .005 or .006
Thank you TezasKZ, hardrockminer, Nessism, Mikaw, and SWest for your help!
Now it's time to get the turd polish back out and finish refreshing this thing.  Looking forward to riding this bike again.  BTW, I didn't keep it all these years because I knew it would be valuable, I kept it because of all the bikes I've owned I liked riding this one the best.

Scotty

sf4t7 wrote:

Update:
Removed cams, set crank at T 1-4, installed cams timed according to kawasaki repair manual, torqued cam cap bolts to 104 inch-lbs.  Engine now rotates free, timing stays correct. Rotated it 10 or 11 revolutions just to be sure, (also to celebrate a little).  I forgot how tiny the arrow on the exhaust cam sprocket is!  While cams were out I covered cam journals, bearings and lobes with engine assembly lube, extra lubrication can't hurt at start up. Clearances are now all at  .005 or .006
Thank you TezasKZ, hardrockminer, Nessism, Mikaw, and SWest for your help!
Now it's time to get the turd polish back out and finish refreshing this thing.  Looking forward to riding this bike again.  BTW, I didn't keep it all these years because I knew it would be valuable, I kept it because of all the bikes I've owned I liked riding this one the best.

Scotty

Be careful, some extra lubrication with the wrong engine assembly lube in a low pressure/high flow engine can hurt at start up!

kzrider.com/forum/2-engine/618780-has-an...aft-bearings?start=0

Scirocco:
I used "Lucas engine assembly lube" same stuff I use when installing automotive cams in Chevy and Ford V-8's.  Will that work ok? The automotive cam bearings look to be a similar design to the Z1 cam bearings with a hole in the bottom surface for the oil supply.

Scotty

I'm happy to hear you were able to re-time the engine without problems.