Cam alignment - How close is close enough?

First time reinstalling the cams after head removal. Following the factory service manual ('81 650 Maxim). The dots on the cams are close, but not right on the arrows.





I'm guessing that this is not close enough??? The manual says to go all the way back to the beginning. Is that really necessary or can the cam caps be loosened and the cams then rotated a little to get everything aligned?

 

There's NO, ... "Close enough"

ALL 3 Timing Marks MUST be dead-on.

Go-back to GO!
Do-not collect $200

 

i just did this on my maxim, and i spent a lot of time getting them to be spot on. what i did was have a friend help hold the cams in place to where i wanted to be and then i slowly tightened the caps back down. they might move out of place a little bit but hopefully you can get a wrench in there to make the small adjustments that is needed. i used a small adjustable cresnt wrench as my motor was still on the bike and had very little clearence, and even then it was a tight fit with the wrench, i believe that it is a 20 metric wrench

 

also i left off the caps on the opposite side so that the sproket bolts could be easily re installed

 

Hard to tell from the pictures but it appears you are off by exactly one tooth.

I've never done cam timing on an XJ, but I think on every bike I've done there was enough slack in the chain (with the tensioner removed) to "walk" the chain by one tooth. Is this not true of the XJ?

If you have to unbolt the sprockets to move the chain I suggest you mark the chain and sprocket so you know where to move the chain.

 

You may be right. I think I'll have to remove the sprockets to get enough slack to shift one tooth back (or forward, as the case may be). Not a huge deal, though.

Thanks for all responses - Rick & Raven.

 

i was the extra set of hands on this once. we took all the bolts out of the sprockets and i held them on the cams. now rotate the cams till the marks are right, then hold the cams there and rotate the crank, chain and sprockets till the bolts line up in the sprockets.
put the bolts in loose and rotate the engine FORWARD till the marks come back up on the cams and check the crank.
you'll need 4 hands, don't let the sprockets slip off the cams, maybe mark the chain and sprocket in case they do.
oh yea, sometimes you'll go the wrong way

 

Hey baytonemus, I have had that many times, where the marks are just a tad off, but move one tooth & you will be way off. If removing the sprockets I link the chain to the sprocket with a zip tie.

 

Before panicking, SLOWLY turn the motor over at least 4 revolutions (2 full cycles) and then see where everything lines up.

Be sure the plugs are out and go very slowly; stop immediately if you feel any resistance. Once the slack comes out of the chain and everything "settles in place" you'll either be on the marks, or need to start over.

 

Thanks for all of the responses. One piece of info that I should have included above: The sprocket bolts are only finger tight. Not sure if that will give me enough play to compensate for the variance.

If I do need to "start over", am I just going back to the point where the cam caps are tightened down but the sprockets are off?

By the way, why did I end up slightly off? I'd like to avoid whatever I did wrong when I proceed with my second attempt.

 

your sprocket bolts have shoulders, right? once the shoulder goes into the sprocket how tight they are doesn't change the alignment.
loosening the caps won't change the alignment either, just makes them easier to turn, maybe.
the cams can't be off anything but links, 1, 2 links, they can't be off 1.5 links or .75 links. there is no way to adjust for that, unless the chain is stretched. or your using adjustable cam timing set up. (your not)
another thing to check is if the "T" mark , the pointer and the piston are really lined up. a degree wheel would tell you which way and how far your off.

 

why were you off, you had some slack in the chain in the front when you lined it all up

 

Thanks, Polock. So I'm closer on my second attempt...





...but still not dead on. When I took the sprockets off I was not able to fully rotate the intake cam without forcing it, so I removed the cam cams and repositioned before tightening the caps back down.

I'm also hearing a "click" as I rotate the motor, but I don't feel any unusual resistance. Seems like it's in the vicinity of the intake cam, but I don't think it's just a valve clicking. Could the chain be catching somehow on the rear damper/guide?

It does look to me like the chain has been broken at some point because there's a master link and I can see that pins have been somewhat amateurishly peened on the back side. Doesn't seem like there's looseness, though, meaning lateral wobble there.

 

I just removed the cam chain tension adjuster and the click I was hearing went away. There's still quite a bit of tension in the chain between the sprockets even with the adjuster removed. Thoughts?

 

by golly, you've done it ! the second picture looks like it's off but like i said before, your either off a whole tooth or your on and that's not off a whole tooth.
you've rolled the motor over a few times in the direction it runs? and that's what you got, your good. as you can be. why is it off a bit? has to be the chain isn't perfect. you said it has a master link. i'am 99% sure OEM chains don't have one. chacal could tell you. the writing on the side link would be a clue also.
i'd put the tensioner back in, by the book and listen again the click could be nothing or it could be bad news. i don't know

 

i am by no means a wizard but the first one looks good and the second is off by just a smigden, but if you cant get a wrench in there to turn it or any thing else than i guess thats what you got. i was able to get mine 'perfectly' lined up, its in quotes because im sure some one else might look at mine and say that its not perfect but it is for me. make sure you crank it around 3 or 4 times and see if the dots line up to the same place as where they started to make sure nothing is slipping and making the cams off, it will also get the engine a bit lubed up and make sure everything turns like it should. in the pics your cams look kinda dry, make sure to lube up your cams with some good clean oil before closing it all off

 

The click is probably from the self-adjuster picking up slack in the chain. It should go away after a few full rotations of the engine.

 

I put the tensioner back on and released the spring, but I didn't tighten it down until I'd turned the engine a few times. That took care of the click. Thanks.

One more thing: I replaced the front chain guide during this procedure. The new one is straighter than the one I took out, so it sticks out past the top planed edge of the head just a little. You can see it in the far left of the first of the two previous most recent photos I posted (at 12:17 p.m.)

When I put the valve cover back on and tighten it down, it will definitely compress that guide a bit. Maybe that's the idea? Just thought I'd check. I'm thinking I might need to "reset" the tension adjuster again once that guide is up against the chain.

 

when i replaced my head i used the old chain guide and i had to take a razor knife and trim down one of the sides just a hair so it would go down into place, maybe you might need to do the same. it should sit all the way down so you can get the 'lock' for it in place

 

That doesn't really sound to me like a recommended procedure, Josh. Did one of the experienced people on this list suggest that you do that?

I decided to put the valve cover on to see how much effort it would take to press the top of that guide down into place. Very little. In fact, it seems to me like this may be the whole idea - to put a little bit of positive spring in that guide.

There was again a little click, but taking the tension adjuster off, reloading it, and then letting it ride freely against the rear guide while turning the motor over several revolutions took care of it.

Now to readjust the valves. Thanks!

 

well it wasnt down the entire side, just on the rounded top parts so it would fit into the holder at the top.

 

There is NO reason why the Chain Guides should need Modification.

They fit just fine before you took them out; so they should go back-in without a struggle.

If you needed to shave the end because the Cover didn't fit; a likely cause if that the lower-end is not seated in the receiving slot that serves as a Pivot Point and locks it from movement upward and SIDE TO SIDE.

There is an external Bolt with Lock Nut that needs to be loosened to allow the lower-end of the Rear Guide to be maneuvered into the notched Anchor and Pivot Point, ... and relocked once the Guide is secured within the Pivots Notches.

 

Valves are adjusted, everything reassembled, and the bike is running great.

BUT... I'm hearing a little ticking that sounds to me like it could be chain noise of some sort. Not sure if it might be contacting the valve cover or some other part of the motor. It's not continuous - it cycles, though not in a regular pattern. I hear it very little at idle. When I rev it up it will be there for maybe for a second or two, then nothing for 3-4 seconds.

As I mentioned before, the chain was pretty tight between the cam sprockets, although if I rotated the motor clockwise there would be some slack. I double-checked the tension adjuster just to make sure that was set correctly. Front chain guide is brand new.

Any ideas?

 

Could just be the chain "making friends" with the brand new front guide.

See what happens when you re-torque the head after a few heat cycles.

 

Doing a Manual Chain Tensioner reset might help.

Try it!

25-minutes.

 

"Manual" chain tensioner reset? Is this something different than releasing the lock nut and holding screw, then retightening?

 

Generally done on Bikes with Auto-tensioners.
Won't hurt to try on manual.

Turn the Engine over manually in the NORMAL direction two full revolutions.
Reverse direction one turn, ... presenting any slack before the Pall.

See if there's any change.

 

Do this with the tensioner "unlocked" then tighten it back down, is that what you're saying, Rick?

 

You have to Unlock it and see it you can make it take-up any slack presented by maneuvering the chain to present any slack on the back-side.

Get what you can.
Repeat the process twice of three times.

Then, lock it up.

 

OK, I got it! Thanks.

 

Make sure the noise is not from a badly seated header gasket.

 

Just went through the procedure you described, Rick, but I think I made it worse. Not sure what to try next.

 

First off, go back and readjust the cam chain per the proper procedure for a manual tensioner.

Then I would take Wiz's advice and carefully examine the headpipe-to-head area; maybe do the "screwdriver stethoscope" trick.

 

Always good advice to go back and re-read the adjustment procedure. My most recent adjustments were not done with the motor in the "C" position. I just plain forgot that small detail. After turning the motor CCW a few times, then parking it at "C" (where it was supposed to be) before releasing the tension adjuster, it seems like I've got it fixed.

Thanks!