XR 600R Cam Chain tensioner

[Jon-D]

What are the running characteristics of a bike with a worn or bad cam chain tensioner? How does a person know when to replace it?

[Beyond The Pale]

Mine started making weird noises. I think the noise came from the chain bucking and slapping around. The noise was easy to hear. I remember pulling up to my buddies at a hang out spot on the trail. As soon as I pulled up there were several comments about the noise. It was easiest to hear at idle or just above. I could not hear it at high RPMs. It only made the noise when hot. It did lessen the power a little, but the engine was still running pretty well.

I was not sure what the problem was. I just guessed the tensioner and/or the chain. The strange thing was back in the garage with a cold engine all seemed normal. The tensioner seemed OK. I replaced both the tensioner and the chain. The noise was gone and has never returned.

[Jon-D]

Thanks Cleonard. Can you give me a run down on how you installed the tensioner?

[Nummie]

I did a complete rebuild on my XL600R, which is similar, if not the same cam chain tensioner.

Lots of detailed pictures here:

http://www.nbdsc.ca/forum/viewtopic.php?t=274

You will have to remove the right side cover and clutch to get at the camchain sprocket on the crankshaft end. It is behind the oil pump drive sprocket, pulse generator rotor, and main drive sprocket on the right end of the crank.

You will have to remove the valve cover, cam sprocket, and cam on the top end.

Since I didn't have the special cam chain tensioner retaining tool I had to improvise. I used a piece of wire to keep the spring compressed while I put the tensioner in place. Once it was bolted in place I cut the wire and pulled it through. Not the most professional technique, but it worked.

You can download the complete Honda XL600R service manual here:

http://www.hondaxl.it/

It will be pritty much the same thing except for the dimensions on the cam, head, piston, rod, and cylinder and maybe a few other minor things.

It can be done in an afternoon if you keep at it.

Good luck.

ps. I forgot to mention that you will need to pull the engine from the frame to remove the valve cover. This means removing the seat, tank, carbs, rear brake pedal, footpegs, and exhaust. Keep organized.

[Jon-D]

cool, thanks for the detailed information!

[Kawabuggy]

Okay, I need some help here... Why is it that everyone believes that you have to remove the motor from the frame to get the valve cover assembly off???????????????????????????????????????????????????????????????????????????

I have seen this same thing said on many web sites-and it just is NOT TRUE~!

You can easily remove the valve cover, jug, piston, with the motor in the frame! It is so easy! I have never owned a Honda before, and I did it my first time and got it off with the motor in the frame in about 20 seconds! Even the Honda service manual tells you that you can take it off with the engine in the frame!

YOU CAN EASILY TAKE THE VALVE COVER OFF WITH THE MOTOR IN THE FRAME! PERIOD! NO FURTHER DISCUSSION NECESSARY ON THAT FACT.

I realize that Nummie is talking about an Xr600L, but John D was asking about an XR600R and that is what I own and KNOW for sure that you can take the valve cover off with the engine in the frame! It's easy! I have pictures of my motor STILL IN THE FRAME with the head off and you can clearly see the number stamped on top of my piston.

For sure you have some work ahead of you with changing out those guides but I don't see a reason it can't be done with the motor in the frame.

[Kawabuggy]

Forgot to mention that you don't have to disassemble the cam chain tensioner to get the cam out like what is shown in the pictures. You can remove the one bolt that will allow the tensioner to rotate around, but leave the rest of it in place. Once the one bolt is out, you can then relieve the tension on the tensioner and wedge it in place with a screw driver, and then get the chain off the cam gear, and then work the cam out after removing the two bolts that hold the cam sprocket to the cam.

[Kawabuggy]

Okay, what is even more confusing now that I look closely at the pictures from Nummie is that he states:

"ps. I forgot to mension that you will need to pull the engine from the frame to remove the valve cover. This means removing the seat, tank, carbs, rear brake pedal, footpegs, and exhaust. Keep organized."

and yet his picture clearly shows the engine IN THE FRAME with the valve cover removed... So, uh, just realize that you can get the VC off with the motor in the frame and his pictures prove it-contrary to what he says.

[HawkGT]

Nice pics Nummie. I love clear pictures of engine guts.

[Beyond The Pale]

Those sure are great pics.

One thing. Be sure to buy both parts of the tensioner. I'm pretty sure that my problem causing wear happened on the center pin, but I replaced both parts just to be sure.

If you are just doing the tensioner and not the chain there is no reason to take off the crankcase cover. However, I would replace the chain too. I did.

[Jon-D]

I got the tensioner in and it all looks like it should. I am still trying to figure out why the bike runs good at idle and a little above, but then it sputters and has that bogged down sound above. I thought it might be the tensioner, which is why I went through the procedure, but no change. The timing looked correct as well. I am completely baffled and am so frustrated that I am considering just parting the bike out. Anyone have any ideas that would make the bike run that way? Is there a timing advance that could be off? Anything?

[HawkGT]

I got the tensioner in and it all looks like it should. I am still trying to figure out why the bike runs good at idle and a little above, but then it sputters and has that bogged down sound above. I thought it might be the tensioner, which is why I went through the procedure, but no change. The timing looked correct as well. I am completely baffled and am so frustrated that I am considering just parting the bike out. Anyone have any ideas that would make the bike run that way? Is there a timing advance that could be off? Anything?

My first guess would be a carburetor problem--like maybe a main jet fell out or a needle clip broke or maybe they just need a good old fashioned cleaning [shrug].

[Jon-D]

My first guess would be a carburetor problem--like maybe a main jet fell out or a needle clip broke or maybe they just need a good old fashioned cleaning [shrug].

That was my first guess as well. Changed out to a known good carb and same results. Does a CDI show these symptoms when it fails?