Timing chain adjustment

[Guy]

This may be something for the Tech Tips
My XJ had about 25k and as far as I know never a valve adjustment. Had quite some vibration at 5k on up. Did some asking and got several ideas. Somewhere along the way I lost a rear support bolt from the muffler, one with the rubber gromet. Well that caused the muffler to crack. Got that repaired then after another nice two up trip I notice the other side cracked, as well as two cracks at the muffler joint, and it's ben welded once before by po. The local shop put me intouch with a restorer. He suggested timing chain and valve adjustment. I have done the chain adjustment by the book several times, even tried with the engine hot, but never felt or heard the spring move. So into the shop and have the valves adjusted. Now, for the tip, Mouse the mechanic says he adjusted the cam tension when he finished the valve adjustment and heard the spring jump. I told him I did that several times and never heard it.Oh! he says I don't do it that way. He runs the rpm up to smooth no clunking and makes the adjustment with engine running , I suppose that takes care of any slack hanging at the bottom. Now with the valves adjusted and tension set, runs really smooth, even sounds different.
Here's the difference. I once let the wife try her hand in the rider seat and I took the back. At that 5k figure felt like my feet were about an inch above the pegs, but now there's barely a hum.
So now with the vibration fixed I have new exhaust system on order to replace the pached originals on the bike now.

Guy

[dntemp_ca]

Yikes! The thought of adjusting the cam chain tension with the engine running makes me vibrate! I'm no mechanic so who am I to judge? But I get little pictures in my head about pieces of XS11 metal whizzing past and thru me on their way into orbit!

[Pat Kelly]

I know all my Hondas called for adjusting the camchain with it running.
I think I'll still follow Yammys suggestion and do it as per the manual.

[Dragonrider]

That's a "pucker factor 10" way to do it if I've ever heard one (on the XS11 engine anyway).

With the adjuster loose, there is enough slack in the chain to be able to jump teeth on the cams or the lower drive (not so on the Honda's...you have to actually remove the adjuster mechanism before there is that much slack).

Turn the engine to the right mark (the right direction) and if you think you may not be getting a decent adjustment, pop the cap over the plunger (front of the adjuster) and push on it gently. (The cap is a rubber-coated freeze-plug thingy and you have to destroy it to get it out, but they are cheap and readily availble from Yammi).

Be careful out there!

[Jerry]

It has been pointed out in the past but may bear repeating.

The shaft of the adjuster can get nicks on it form being over-tightened. These nicks will prevent the shaft sfrom sliding properly during the adjustment procedure. I suppose that the vibration from a running engine might help the shaft slide, but the real cure is to remove the adjuster, polish the adjustment shaft smooth, and go by the Yamaha manual.

[skids]

There used to be a small mechanics shop where the guy said he could hear my cam chain a block away and tried talking me into having him do an adjustment. I asked him how he did it (to see if he knew enough about my bike) and he said he did it with the bike running. I had already done an adjustment and really, the noise was barely audible. I seriously doubted his method and didn't take him up on the deal. I believe that the only real way to do it is by the book. BUT, if your mechanic did your adjustmentment and you are happy with the performance, who can argue with that?!

[Ken Talbot]

I've been thinking about this a bit, and I think I can sort of see how this might work.

When the motor is running, the crank is being turned much like it would be when being turned the correct direction by hand. This puts tension on the rear side, i.e. on the side of the chain pulling the camshafts around. The other side of the chain is where the slack is, and this is exactly what the textbook adjustment method is supposed to achieve. Theoretically, if you loosen the adjuster in this state it should spring itself to the needed position whether the motor is running or not.

Do I think this might work - yes. Would I be willing to try it on one of my XS11s - NOT IN A MILLION YEARS.

YMMV......

[randy]

I've been reading this thread for a while and at first I thought it was a joke, but now I can't resist putting in my $.02.

Sounds like voodoo mechanics to me. The reason the procedure calls for doing the adjustment at the "C" timing mark is because that is the point in the rotation where there is maximum slack on the chain. The point of the adjustment is to remove the slack.

Loosening the lockbolt with the engine running will set the tensioner rail flapping in the breeze as the chain cycles between slack and tight.

Then when the lockbolt is tightened down, ( I assume while the engine is running), is it by sheer luck that the proper tension (minimum slack) is achieved? Believe that one and I've got a bridge for sale in Brooklyn!

If Yammi engineers thought that the tensioner spring would do the job by itself, they would have fitted a stiffer spring and left out the lock bolt mechanism. Or, better yet, they might have fitted a hydraulic tensioner similar to a hydraulic valve tappet.

No, I wouldn't make the adjustment with the engine running. Yammi engineered it this way because they WANT you to check it periodically. So that when you do it and no longer hear the 'click' of the plunger, it's a warning sign that it's high time for a new chain.

Just my $.02.

Randy

[skids]

Although I am in agreement with out on the adjustment technique, I think that you will not hear an audible click unless your chain was way out of adjustment. The audible click is most pronounced and necessary when you have removed the adjuster, cocked it, reinstalled it, and released the stopper bolt.

Originally posted by randy


So that when you do it and no longer hear the 'click' of the plunger, it's a warning sign that it's high time for a new chain.

Randy

[ricoc]

Guy, your mechanic must have mouse ears. He heard the click over the engine running?