Cam chain adjuster question

[75steve]

The engine on my 77 XS650D has a tick that I can't locate, so I thought I'd try a rubber washer on the cam chain adjuster. After pulling the adjuster, I noticed that when the adjuster, with the original washer, is jammed up to the shoulder on the rod, the back of the rod is flush with back of the adjuster. Does this look right? There doesn't seem to be any way to tell if the adjuster is too tight.

The last time I adjusted the cam chain I noticed there wasn't very much in and out movement on the adjuster rod, maybe .5 mm. I've got around 10K miles on an OEM cam chain from my local Yarmaha dealer.

 

[rebel542]

Looks right to me. Your tick is probably an improperly adjusted valve.

 

[weekendrider]

Adjust it till it is flush then feel/watch it while running.
You want it to bob in and out 1-2 mm. If it doesn't it is too
tight.

 

[richardthemotorcycle1]

Is this the rule of thumb for all XS650's? (1-2mm)

 

[smokedyerstang]

This is what I've always gone with.(1-2mm)

 

[richardthemotorcycle1]

Thanks

 

[5twins]

Be aware that if you use the newer rubber/metal damper washer on your older tensioner, the rod will no longer come out flush with the end of the screw when set properly. The new washer is thicker than the old copper one. The rod will be inset a bit which makes observing its movement more difficult.

I don't think the type D assembly with no lock nut was a good idea. Apparently Yamaha felt the same way. They used a lock nut on all the earlier tensioners and returned to using one on the next assembly after the D, the type E .....

You can upgrade your type D assembly by simply swapping in the rod and locknut from a type E. All the other components are the same. The type E works better with that thicker rubber/metal washer as that was the assembly it was designed for use on.

 

[75steve]

Hey thanks. I never took a close look at the adjuster when I had the motor apart. From the adjustment procedure and images in the manual, I expected a little space between the adjuster and shoulder so the rod would protrude through if it was too tight.

I didn't think the .5 mm rod movement was right, I had seen the 1 to 2 mm mentioned before, but the rod was flush with the end of the adjuster. I'll pay attention to the movement when it goes back together.

To 5twins: Yes, I measured the rubber washer and it's slightly more than 1mm thicker than the stock copper washer. I figured I'd make a simple gauge to get it close and if it worked I'd grind off the end of the screw. I may try to locate the type E parts.

To rebel542: The tick sounds like the right exhaust, but it's not. I've probably check the valve adjustment a dozen times. It's kind of a hollow tick, resonating through the engine so it's hard to located. It started between 1K and 2K miles after I rebuilt the engine. I've put around 8K miles on it since it started and it hasn't gotten any worse. I've been searching the old "tick" threads to get some idea of what to try and the rubber washer seemed easy. The bike has always run good, but that tick drives me crazy. I'd like to figure it out, in the meantime I'll ride it till it breaks.

 

[XSLeo]

Use a long screwdriver, hold the handle to your ear. Touch the point to the engine, touch it all over. You can find the noise this way. A mechanics stethoscope works a bit easier.
Leo

 

[75steve]

Use a long screwdriver, hold the handle to your ear. Touch the point to the engine, touch it all over. You can find the noise this way. A mechanics stethoscope works a bit easier.
Leo

I tried that. I even soldered a welding rod to a tin can so I could hear better. It seems loudest at the right side edge of the top case half right behind the cylinders. Last winter I pulled the engine, checked out the top end and split the cases. All the crank bearings were good. The oil pump and tach drive were fine, they're more to the front anyway. The only thing I found is the cushioning springs on the back of the clutch assembly may be worn out, but I don't know if that would cause a tick.

I tried the rubber washer on the cam chain adjuster, didn't help the tick, so I went back to the stock washer to keep the adjustment simple.

 

[TwoManyXS1Bs]

I tried that. I even soldered a welding rod to a tin can so I could hear better. It seems loudest at the right side edge of the top case half right behind the cylinders...

I like that, a stethoscope 'boom box' version. Could try to determine if the tick is synchronized to the crank or clutch. The primary drive reduction is 2.667:1. An engine idling at 1200 rpm rotates at 20 revs per second. A 20 hz tick would be crank related, an 8 hz tick would be clutch or mainshaft related.

Could also see if it still ticks with clutch pulled and trans in gear. If not, that eliminates the mainshaft and trans.

Sound travels best thru the webs (like inline/aligned with the cylinder studs) and thru clamping screws (probe in the sidecover screwheads).

A bad crank bearing will have more of a 'whirr' than a 'tick'.

Here's a bulletin on primary gear lash: