Cam Chain Timing

Thanks to the members who supplied me with the info on kz650 timing.I received a new head gasket and tune up kit from z1. excellent service. I set everything up as specified, except removing the chain tensioner. Every time I turn the engine clockwise a quarter turn, the timing belt jumps and back to square one again.I have the top tensioner in place,but the chain seems pretty loose.I have the engine timed again on the cams,#1 piston tdc. How do you turn it over to get the slack out of the chain before I replace the chain tensioner on the back of the motor?NOT GIVING UP TILL IT RUNS!Old bike,5000 miles,motor #kz650BE003754,anybody got3755?

If you have the cam chain tensioner off while doing this, you will have too much slack in the chain, and it will jump out of position.

You want the tensioner on there as Rob said before you ever turn the engine over, however you can, if you like, use a screwdriver or other tool to press in on the chain guide while the tensioner is off to simulate what the extended rod in the tensioner would be doing if it was there. Why in the world are you removing the tensioner anyway? It never needs to be removed or even touched during camchain timing/camshaft removal.

RonKZ650 wrote:

You want the tensioner on there as Rob said before you ever turn the engine over, however you can, if you like, use a screwdriver or other tool to press in on the chain guide while the tensioner is off to simulate what the extended rod in the tensioner would be doing if it was there. Why in the world are you removing the tensioner anyway? It never needs to be removed or even touched during camchain timing/camshaft removal.

FYI, my KZ750 Four workshop manual says to always remove the tensioner before removing the valve cover. Are you guys saying this is wrong?

apeman wrote:

FYI, my KZ750 Four workshop manual says to always remove the tensioner before removing the valve cover. Are you guys saying this is wrong?

No, you have a 750 and the question is about a 650, and there are differences.

The 750 has a cam chain guide mounted to the top of the cam cover that presses down on the cam chain when you install the cover, the 650 doesn't. The 750 has a HyVo cam chain while the 650 in question appears to have a roller cam chain.
The 650's went to the HyVo style in 81 or 82 I think.

Post edited by: steell, at: 2007/01/27 08:55

Even on a KZ750 there's no reason to ever remove the tensioner. (I'm talking 4 cylinder models, and of the tensioner mounted on the block beneath the carbs). I'm surprised if a manual says to do this, because it's not necessary and serves no purpose. On a pre 1979 KZ650,900,1000 with the manual tensioner, just leave it alone and when you reinstall your camshafts, the chain will be tensioned exactly the same as it was prior to disassembly. On a 1979 up KZ650,750,1000,1100 ect, with the auto tensioner you need to remove the short 6mm bolt on the tensioner and replace it temporarily with a long 6mm bolt to lock the tensioner from moving, then do your camshaft service, and when done simply remove the long bolt and reinstall the short. That's all you ever have to do to the tensioner.

Boys, thanks again for the info. I neglected to inform you that I had to replace the cyl. head due to major oil leak around #1 piston.The head was cracked between two cooling fins in this area. tried welding,didnt work.Now back to cam timing and this rear back engine chain tensioner.When any of you ever have a problem like I had,the manual dont tell the whole story.You will learn,like me,after five teardowns,that experience is the only and best teacher.When you have the engine timed on the cams.with the tensioner out,slowly turn clockwise on the points cam,17mm. wrench.with your finger on the flapper in the tensioner hole .As you rotate the engine ,slowly,you will find the flapper moving inward.This tells you the cog on the other side of the flapper is taking the slack out of the chain.Repeat rotation of engine until the flapper does not move in anymore. Let pressure of flapper gently.reposition plunger back in housing and tighten set bolt.bolt tensioner back to engine.Slacken off set bolt,you should hear the tensioner spring in place.Rotate a few more times just to be sure.Your done.Fired her up this morning,running pretty good after 30yrs. in storage.Never give up!If its got compression,got fire,got fuel and is timed correct it has to GO! Tnks boys for the help.Im staying around on site.

Just thought of something I forgot to mention on timing chain tensioner.As the engine is rotated clockwise on the points cam,DO NOT move anticlockwise until all slack is gone from timing chain.If the chain slips one tooth one the cam,your back to square one. When setting gap on points, better to keep going clockwise on rotation of engine than one little twist of the wrench in reverse.Been there,done it.Tnks again.

Hey Ron I just put my camshafts back in with those shims you gave me and they are all perfect now. Only today I actually followed the instructions in the manual( I ran into trouble this time with timing). I have a manual tensioner on my 650 now and I basically backed it off to make my work a little easier, get more slack. However I put that chain pulley that goes on top between the camshafts before I turned it over to check timing. The first time I timed the cams today I had to take them back out, so I removed the center pulley and left one of the rubber dampers in position, and when I moved the pulley the thing dropped inside the engine. I was so mad, plus the backbone of the bike frame was blocking me from seeing inside the thing, plus I couldnt keep calm. I couldn't touch the chain for fear I might really loose the thing in the case somewhere. Tried using my magnetic screwdriver, since I don't have a magnetic stick or something like that, so I put a allen key in the driver to reach it and a little bit of magnetism attracted it, but it wasn't enough. I finally decided to get a piece of wire and hook it to get it out and I did. So I was good to go then it got really cold.