Thanks for the replies, I haven't taken the cover off yet, but probably will next week when we get rain. The weather here (NE Ohio) has been so nice and I wanted to take the opportunity to let my sister "learn" how to ride a bike again, mostly parking lots. So far, so good, no increase in the random ticking but is sure hasn't gone away. After today the bike will probably get mothballed until the clutch cover gasket shows up. I should have ordered a tensioner too since if it is about to fall out there is a good chance that the bore is worn so bad I wouldn't want to use it again. I just couldn't stomache paying the money for the tensioner until I had the cover off. If the tensioner is about to pop out I am planning on doing the mod listed here since I have a MIG/torches and full access to a machine shop. I was also going to get a hardness reading on the tensioner prior to welding or modding it but I don't see a problem with using a MIG on the hole end, it should keep most of the heat away from the cylinder/piston side (which may be hardened for wear). I will keep people posted. The collective info on this site is better than any manula I've ever had!
Rick

Remember the posts earlier. people ordered the "tensioner" ecpecting the spring loaded part & got the rear guide, whic touches & does tension the chain. The Tensioner Adjuster is the spring loaded part. IF I remember correctly, make sure you know what you are prdering or risk disappointment.

I don't mind at all.  Please credit me though.

After reading both manuals, and this forums threads 10 times, tightening every bolt four times, scraping, and polishing, I finaly got it back together.  And went for my first ride this morning.  My 1st major wrenching in 20 someodd years.  And she purrs again! dam I'm happy.  So happy I nearly plowed into the back of a van with no brake lights.  Now that I'm sober again, I can get back to business.

After I put a 1000 miles on her, I'll open her up and check the state of the tensioner.

If anyone would like one of these made up for them, I will open a store in the marketplace.  I have access to certified welders and a mill.  The option will be new or rebuilt parts.  

This is what was making that intermittent ticking sound, like there was a little piece of metal getting flipped around inside the clutch cover (if I was lucky). The tensioner rod was close to coming out of the body on my sister's 1987 (supposedly has around 8000 miles, doubt that!)

Whole Cover


Close up of tensioner, ratchet is off of last serration in rod, out of travel


Chain is within about 10mm of touching itself

...and BTW, Mr trooper, from the looks of your pics, if you get the extension welded on what you have now, all you would need is a clutch cover gasket.

K1200LTryder wrote on 12/31/69 at 16:00:05:


Better raise the idle to Suzuki specs. 1100-1200 RPM.
Gives the head the oil it's needed.

OK, I took some measurements at work just for informational purposes on my used cam tension adjuster. I measured the hardness of the eye end of the piston/rod using a Rockwell Hardness tester (C scale) and measured the spring rate as the tensioner extends on our spring force deflection machine.

The piston/body is hardened steel, between HRc 53-55. I can't really tell if it is case hardened or thru hardened, it would have to be sectioned up (read that destroyed) and I would have to run a microindentation or microhardness test a radially points  through the part using Vickers or Knoop tests to see how the hardness varies.

For reference purposes, a Grade 8 bolt  typically has a hardness in the range of HRc 33-37. The piston/body is significantly harder and stronger than a Grade 8 bolt.

I measured the spring rate of the compression  spring on our rate measuring machine. My spring had a rate of @ 3.9 lbf/in. I also measured the force to just hold the piston from ratcheting to the next position at both extreme assembled positions (ie. highest and lowest forces). With the piston all the way into the bore it took @ 6.8 lbf to hold it from ratcheting to the first position outward, whereas with the piston about to come out of the bore, on the last serration, it took @ 3.3 lbf to hold it in.

Like I said, being an engineer I am curious why this set-up seems to cause problems in engines with what I think is minimal mileage. No one seems to have good data on how much the tensioner sticks out when the engine has little or no miles. It would be better to have data with some break-in miles because I am sure the initial wear-in is considerable as things seat together.  Looking at a freshly built engine with new cam chain parts would most likely be a lot different than looking at one with 500-1000 break-in miles on it. Just put a new chain on a bike, set the chain slack and run it for a few hundred miles and then check it again. I bet you have to adjust it tighter (I have done this so many times in my kids and my years of street and dirt bike riding that I would like to forget it). After the initial adjustment and wear-in period things tend to "quiet down" and the adjustment period is much, much longer.

One other thought I had was how much the thermal expansion/growth of the aluminum parts between the crankshaft centerline and cam centerline at temperature tightens the chain. We only have the ability of looking at the tensioner assembly in the  cold state when I believe it would be at its loosest. Does running hot cause the chain  to be overtightened and accelerate its wear(since the ratchet is one-way ( probably pops to the next notch when cold and maybe is then overtight when hot)?  Just thinking out loud.

Hope someone eventually figures this out.

Rick C. (whose sister is the newest member of the cam chain club and I get the lucky job of being her mechanic)

Slavy/Verschlagen Nice   mod. I was thinking from the other end and trying to avoid welding, heat-treating/hardening.  Out of 4130  bar steel (or square steel) machine a small (diameter of plungerhousing)  Y shaped tuningfork. Drill holes (2) in open end and bolt  onto plungerhousing making sure that open end fits tight against plungerhousing. Drill the other hole with desired bore-spacing and mount to existing dowel/stud using original circlip. This all is best made with milling- machine and drill-press. I've got a drawing. No need for me to make one now since I do not have a S40 yet!! My friend tell me I'm grazy to buy a machine with a build in handgrenade whose pin gets pulled by time. But I like thumpers and don't mind tinkering. Still riding my bulletproof 650 GLi Silverwing bought new in '83.
Keep smiling