79 KZ650 SR: Camshaft Reinstall, Timing Marks Not Matching Up

Hey all, first post here! 

Was recently given a 79 KZ650 SR from a friend in very bad shape. P.O. did a lot of shoddy maintenance, so sorting through a lot. Began a valve adjustment procedure and removed both camshafts because 5 valves needed new shims. I cannot for the life of me get these camshafts back in and lined up on their marks. I followed the Clymer manual and also RonKZ650's post: 

Post #249136 by RonKZ650:
Of course you need to tighten the cam caps, and the cams will settle in place and you'll have your slack. No way the cam can ever lay flat until you fully install. So line the T mark up on your advancer, look at the arrow on the exhaust cam and visualize where it will line up when the bolts are tightened, torque the cam down enough for it to be fully seated, look at your arrow and if you've guessed wrong by a tooth or two, go back and redo. After the exhaust is lined up, count back your 36 teeth and line the intake cam there, torque the intake cam, then press down on the chain between the cams to get enough slack to install the center idler sprocket, turn the engine clockwise slightly to take slack out, then install the tensioner if it's been removed, turn the engine over 1 revolution to the T mark and see both arrows lining up correctly with the head. There is no reason to ever remove the tensioner when removing the cams because on pre 1979 manual tensioner it will stay set right where it was, on 79-up lock the tensioner as instructed in the manual.

In my case, the camshafts were all lined up, timing marks pointing right at the cylinder head, timing cover at 1/4 TDC. All is good until the point where I put the cam chain tensioner in. My KZ has the automatic tensioner, and I followed the reinstall procedure for it (depress the plunger all the way, reinstall, loosen lock bolt, let it take up slack). However, when I do this step the intake cam gets pulled down another tooth or so, and the timing mark ends up below the cylinder head while the exhaust cam stays right where it should be.

I thought no big deal, I can just move the intake cam up a little bit so when the tensioner is installed, itll pull it down to where it should be. However, I cant do this because there isn't enough slack on the chain for the intake cam to go high enough. Currently, both the camshaft timing marks line up about 1mm behind the TDC mark, kinda right where the "T" mark is, not where the little mark is after that is true TDC. I'm not sure I'm not really sure what to do, I've taken out and reinstalled these camshafts no joke probably 20 times over the last two weeks, trying to figure this out. Is the chain stretched? Any help would be greatly appreciated. 

Welcome to KZRider 
Please make your next post a introduction in our new members forum.
Once done you can post in this forum
Dave
Site Moderator

Copy that!

Does your motor have a rubber guide in the cam cover and a hyvo chain - if so you need to refit the valve cover before activating the tensioner or the timing will be off and the chain too tight

Technically, if it is 'nominally' a 79, still has the center idle sprocket, and a roller chain.   HyVo and rubber guide started in '80 with the introduction of the 750 four

I don't know on this set up, but on newer 650 and 750 fours with guide and HyVo, when timing is set correctly, and link count is correct, the sprocket markets align perfectly only w/out the cam cover(and guide off).   

Once sag is induced to install cover WITH RUBBER GUIDE, then ovbiously intake cam rotates a bit (forward) and sprocket marking will move away from horizontal.  ...Meaning, once everything is buttoned down and slack taken up, intake marking will not be perfectly aligned, ...but does not mater as long as link count between sprockets themselves, and crank is preserved.

In his case the center idle sprocket takes the place of the rubber guide.   Don't know if instruction for timing are with or w/out center idler. 

If timing set correctly, Important thing is not JUMPING teeth on sprockets or crank......markings may rotate a bit creating sag or tensioning. . 

I'm not 100% sure I completely understand the issue, but line up your exhaust cam correctly first and go from there. There is no slack in the chain up in front, so once it's lined up, if you count your teeth, which I forget the number off hand, but 28 or whatever, then the intake cam should be correctly timed. Install your center roller and turn the engine over by hand, the lines should line up with or without the tensioner. 

DartagnanPHd post=926882 userid=83675
In my case, the camshafts were all lined up, timing marks pointing right at the cylinder head, timing cover at 1/4 TDC. All is good until the point where I put the cam chain tensioner in. My KZ has the automatic tensioner, and I followed the reinstall procedure for it (depress the plunger all the way, reinstall, loosen lock bolt, let it take up slack). However, when I do this step the intake cam gets pulled down another tooth or so, and the timing mark ends up below the cylinder head while the exhaust cam stays right where it should be.

I thought no big deal, I can just move the intake cam up a little bit so when the tensioner is installed, itll pull it down to where it should be. However, I cant do this because there isn't enough slack on the chain for the intake cam to go high enough. Currently, both the camshaft timing marks line up about 1mm behind the TDC mark, kinda right where the "T" mark is, not where the little mark is after that is true TDC. I'm not sure I'm not really sure what to do, I've taken out and reinstalled these camshafts no joke probably 20 times over the last two weeks, trying to figure this out. Is the chain stretched? Any help would be greatly appreciated. 

To answer your last question, yes the cam chain is stretched. You didn't indicate the mileage but for sure you have over 8K miles on it, and I would not doubt that the cam chain is stretched a little. I have never seen a used KZ engine where the cam sprocket marks line up with the "T" on the case perfectly. If you replace the cam chain that's a different story.

They will start and run a whole tooth off. Stock 650 engines have a lot of built in room as far as piston to valve and valve to valve is concerned. As long as the exhaust side is good and the pin count is good I would not be worried about the hash marks not lining up. I have a KZ750 Spectre where the marks are way out and it runs just fine.

That first paragraph looks OK to me, I would not fret about it. You need to rotate the cams around a couple of times by hand to make sure there are no issues. If you not sure Stop, get a zip tie and a flash light to make sure you have piston to valve clearance on both intake and exhaust on #4 piston before you start it. You will tell right away if its a tooth off, they sound "weird" and laggy.

I would look into that tensioner if I were you, they are prone to issues if you have the later version. 

I stopped using the "T" mark years ago and use a TDC stop as its much more accurate. That's how I setup my 750 with the stretched chain.