Help. I took the cover of and right enough the tensioner is sagging down just about out. Quandry! Do I weld an extension lug on the end or replace the chain?. can anybody advise me on the life of a chain,the bike has 19635 miles on it and I don't know if the chain has been replaced. Can I replace the chain with the engine in the frame and is it a major undertaking,,cheers,,kenny

minor problem. Got tensioner off and the chain looks ok going to leave it to the winter then whip engine out. To get me going just now, going to weld extra lug on to end of tensioner then drill out whole but can anybody tell me if it is made of mild steel or some kind of alloy,,cheers

The full answer on your chain wear life goes like this:

(source:  Morse Engineering, the people who make the chain.  We sent them a "worn-out" chain for analysis when we were spec'ing out the improved group buy chain).

It has been noted many times that our chains are still well within shop manual "service spec" when they are no longer tensioned correctly by the tensioner because it is totally out of adjustment range.

Morse cut apart a worn out chain and analyzed the wear on the pins.  It was all normal, smooth, properly lubricated (non-gauled) wear.  It was also at the 10% of total service life level as far as depth of wear goes.

I brought this returned cut-up chain and sprocket to the mountain trip and we spilled it out on a McDonalds table and spent time looking at it.  You could see the shiny spot and you could feel the wear with a fingernail -- this wear was on the order of .001-.002" deep.

Now you know why we spec'd a super hard nitrided case for our group buy chains that had a nitride penetration depth of .005-.010" deep into the steel and a build up of superhard surface residuals on the order of .001-.002" deep.  For what we are going to actually engage in wear depth during a full Verslaggy mod double-life-run, we have a material on the order of carbide to wear against.   Then we finally wear down to something akin to a stock chain ....

But we still have a tough resilient steel core to the pins and the plates.  We will not break these chains even on a heavily modded thumper.

Folks don't like to think about it, but if we could figure out a way to adjust our chain from both sides in a "Z" fashion, we might get a chance to use up all the "standard wear life" of a Morse/Group Buy silent cam chain.

You guys that have experience with other engines need to chime in here.

But what I do believe is that we need a new tension adjuster design.  

I would need a glass sided engine to know for sure.  But what I think is the serrations on the pawl are probably too fine.  I don't know if it's the temperature cycles that progress the pawl or actual wear or motion.  But I think something is causing premature wear on the guides by overtensioning the chain.

I will surmise that rapid change in rpm's causes a wave of tension/slack in the chain.  And this is why we have a rachet and pawl.

I also noted that there's quite a bit of room behind the adjuster and it could have been twice as long.

And I'm also concerned with the present chain.  

Especially Yonuh's experience of the chain actually snapping on him.  He noted that there was spots in the chain that would kink and stay that way.  That may be the reason why the spring in the tensioner is made stiffer now.  All it would take is for one of these kinks to engage the case jamming the gear... and snap goes the chain.

I also want to map the wear against the TDC to see if there is more stretch/wear at certain point in the cycle.  My chain has been r&r'd once so it might have 2 patterns of stretch.  I need a chain for someone who's never had it off.  It needs to be marked while the engine is at TDC at a know location such as BDC of the chain.

And Justin... the answer to your question is here.

http://suzukisavage.com/cgi-bin/YaBB.pl?num=1192027390

I read somewhere (fssnoc?) that there was a manual adjuster conversion for one of the other bikes.  And to adjust it they screwed it up tight then backed it off x turns.  Fortunately they have an inspection cover.  We don't have exterior access to make an adjustment.

I may be wrong here, but there are a few points I do not understand / agree with :

1) I do not believe the cam chain will have tense/slack cycles as the engine revs; the cam chain only has one load, the camshaft itself, and that load is, IMHO, constant because it is provided by the valve springs. On the other hand, the transmission will have such tense/slack cycles as the bike accellerates, then coasts, because the load changes.

2) I do not know if we could really have a two-point tensioning system... but has anybody ever considered swapping the current cam chain sprockets with other sprockets from some other bike, so as to change the build quality of the cam chain itself ? Yamaha, Honda, Kawasaki? Aprilia, BMW, Suzuki DR ?
KTM ???

Who knows... ity might just work...

Valve lift is the load.
Valve drop will give it a kick.

With the current set up, adding a manual adjustment to the front w/o opening the cover and resetting the auto adjuster will cause binding of the chain.

Which is why we have discussed replacing the stock tensioner unit with a hydraulic dampner based spring loaded unit, so we can put a manual adjuster to the right side to mate with the hydraulic on the left side.   Left side would self adjust to the slack being removed from the left side and moved over to the right side as the mechanical moves in.

Put it in perspective, if we don't do something we will have to open our engines up every 2-3 years to work on the cam chain drive system (those of us who pile on the miles, anyway).  4-5 year time span for normal people.

With a total range of motion self-hydraulic-stop-adjusting tensioner on the left side and a mechanical (outside accessible) adjuster on the right side you could do this trick.  Tightening the right side would move the left (hydraulics would give at the very slow pace of mechanical adjustment movement) until there was a tight chain on the left and you would feel a stop point on the right side mechanical adjuster.  

Back right side mechanical off 2 turns and lock it down.  Hydraulic dampner on left moves forward to catch that small amount of slack, leaving you with the full range of left side hydraulic adjustment (less the 2 turn take up).   Go ride for 10,000 miles and then do the drill again.

Eventually, right side mechanical goes in all the way and is locked down, then you just wait & listen for chain slap that signals the chain has finally worn out.  We should get 3x mileage out of the cam chain, at least.