Manual Cam Chain Adjuster

[meosborn]

But if you wish I will tell a short story. I had a XS 11 yamaha which had a manual cam adjustment. It had the piston mate up with the valves because the manual adjust screws(actually nut and bolt arangement) suddenly moved on start up and connected. That's the short story.

Assuming you are describing an adjustment screw/bolt/rod with locknut (and that's how I read it) then the only way the adjust screw could have moved is if the locknut wasn't tightened thoroughly/correctly. How is that the manual CCT's fault?

I would assume you could say it was the manual CCT's fault because there was a locknut that you had to be concerned with tightening correctly.

I can understand why many want to take the weak CCT out of the equation but I'm not sure that I want to replace it with a manual version. I personally would rather replace my spring loaded CCT every 20k miles than have a CCT that I have to adjust manually.

I do like the idea of finding a automatically adjusting CCT that is more reliable though. Until then, I just replaced mine with another OEM Yamaha part from Gary for about $75 including shipping and a new gasket. I've only got about 42k miles on my '03 so if I have to do it in another 7 years I'll be fine with that.

I should ride more. <_<

 

[RadioHowie]

I would assume you could say it was the manual CCT's fault because there was a locknut that you had to be concerned with tightening correctly.

It's Sunday, so I've got most of my brain in "day off" mode and may have missed the humor, but still, you're kidding, right?

That would be like saying it's your gas tank's fault for going empty and stranding you outside of Area 51 because you had to be concerned about filling it.

 

[JuiceMcGoose]

If you feel like reading Google: manual cam chain tensioner. Bikes that have had problems with their auto CCT include Gixxer's, CBR600's, ZX-6RR's, and Triumph Daytona 675's, plus various others. One guy did a write up on installing a manual CCT on the BMW GS that looked like a big job. Apparently if you install one on a ZX-6RR you need to safety wire it because red loctite isn't enough to hold the bolts in.

The distances I've seen that people go before re-adjusting it vary between 3k and 10K miles. Most people know when to adjust it by the sound it makes.

A number of people have loosened the adjustment too much, skipped a tooth on the chain and bent their valves.

From what I've read the best method of adjustment is put the bike in 5th gear, turn the rear tire forward so the engine moves and tighten the adjuster bolt finger tight lightly. May have to remove some or all of the spark plugs. Mark the adjuster bolt. Move the tire/crank and finger tighten the same amount. Do this several times until you find the spot where the chain is at it's tightest point and tighten the adjuster. The idea here is chains often have loose and tight spots and you want to tighten it at it's tight spot.

 

[Fred W]

From what I've read the best method of adjustment is put the bike in 5th gear, turn the rear tire forward so the engine moves and tighten the adjuster bolt finger tight lightly. May have to remove some or all of the spark plugs. Mark the adjuster bolt. Move the tire/crank and finger tighten the same amount. Do this several times until you find the spot where the chain is at it's tightest point and tighten the adjuster. The idea here is chains often have loose and tight spots and you want to tighten it at it's tight spot.

That sounds like an interesting mental exercise, but probably not necessary.

Consider what happens on a CCT that has a ratcheting anti-reverse feature. The spring (or oil pressure force) causes the tensioner to take up all of the slack at the slackest part. If that happens to be enough to slip the ratchet pawl over the next detent, then it will latch at that point never to go backward again. As the engine continues to turn, when the chain hits the tighter spot(s) it doesn't seem to matter.

 

[meosborn]

That would be like saying it's your gas tank's fault for going empty and stranding you outside of Area 51 because you had to be concerned about filling it.

Partially I suppose, if there was another option in gas tanks, as in one that filled itself. It obviously doesn't make a lot of sense placing blame for anything on an inanimate object. I just meant that the fact that a manually adjusted CCT must be adjusted manually (amazing) and this may be considered to be a drawback to some. Drawbacks are the "fault" of whichever design we're talking about. For example, the OEM CCT might fail and ruin your engine because it wasn't replaced in time. The lack of any external indication that it needs to be replace is a drawback and the fault of that design.

And I never joke (post #27 was completely serious). That would deprive you of another opportunity to tell me how stupid my opinion is.

 

[Zorlac]

"I never joke "

Damn, I feel sorry for ya.

 

[radman]

The XS Yamaha's would adjust while the motor ran. A plunger would move in and out as chain slack moved it. When properly adjusted, the plunger mostly stayed flush with the housing. I like the spring idea-tension without locking, allowing some movement in chain slack without risking inadequate tension.

 

[Fred W]

For example, the OEM CCT might fail and ruin your engine because it wasn't replaced in time. The lack of any external indication that it needs to be replace is a drawback and the fault of that design.

The problem with the above statement is, what is "in time"? And will it be the same amount of time the second time around (with a pre-stretched chain)?

A manual chain tensioner will let the owner know that "it's time" to adjust by a very gradual increase in chain noise. But even though there is noise (and some slack) there will not be enough slack to skip a sprocket tooth unless the noise is ignored.

The OEM tensioner will give no such warning and can be slack one morning when you thumb the starter with no previous warning at all.

Surprise!! Today is you (un)lucky day... :angry:

I may buy something else that fits, or replace with a manual tensioner, but I will not be replacing mine with an OEM tensioner that is already known to be of a defective design.

The XS Yamaha's would adjust while the motor ran. A plunger would move in and out as chain slack moved it. When properly adjusted, the plunger mostly stayed flush with the housing. I like the spring idea-tension without locking, allowing some movement in chain slack without risking inadequate tension.

Isn't that the same as the stock tensioner flaw? I think any time you have a spring loaded tensioner with light enough spring force (to prevent guide wear) you will risk the plunger retracting and allowing the chain to skip, unless there is an anti-reverse feature in it.

Maybe if the spring stroke was very limited it would be act as a hard limit, an anti-reverse? Like you adjust it until the spring is fully compressed then back off only 1/4 turn of the adjuster. That would be good when installed, but then what happens as it wears? There would be increasing amounts of spring stroke available as the chain, sprockets and guides wear, eventually may be enough to skip a tooth?

 

[FJRay]

The tensioners that I have had apart with compression springs have a pretty stiff spring and don't seem to have guide wear. The springs on both my Concours and the KLR were very stiff. The spiral spring in the stock tensioner looks like it came out of a watch and there is nothing to keep it from backing off. I think the idea of the spring to absorb shock and provide for tight or loose spots in the chain is good and why it is used by most. Whether it is backed up by a ratchet or a manual adjuster doesn't matter a whole lot as long as you do regular service with the manual method.

 

[huron52]

The XS Yamaha's would adjust while the motor ran. A plunger would move in and out as chain slack moved it. When properly adjusted, the plunger mostly stayed flush with the housing. I like the spring idea-tension without locking, allowing some movement in chain slack without risking inadequate tension.

Not quite sure the plunger moves in and out as the chain slacken....

From the XS11 website...

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Adjusting the Cam Chain Tension

An out-of-adjustment cam chain can cause the bike to run poorly andvibrate. To adjust the tension, locate the tensioner on the front of the engine between cylinders 2 and 3 - it's that little do-hickey protruding from the cylinders with a bolt sticking out the left side. Remove the engine case cover over the timing plates and use a wrench to manually rotate (clockwise) the engine until the timing pointer aligns with the "C" on the timing plate. Then loosen the locknut on the cam chain tensioner, loosen the bolt, then retighten the bolt and then the locknut (specified torque is only about 5 ft/lbs so don't overtighten), and replace the case cover. That's it.

******************************************************************************************

******

So it appears to me that the plunger is spring loaded and once you have the timing point aligned with the "C" you loosened the locknut and let the plunger move in on it's own until it bottomed on the guide inside the motor.

Then retighen the locking nut...

The plunger can't move because of the locking nut.... and the tightness of the bolt on the plunger shaft.

 

[meosborn]

For example, the OEM CCT might fail and ruin your engine because it wasn't replaced in time. The lack of any external indication that it needs to be replace is a drawback and the fault of that design.

The problem with the above statement is, what is "in time"? And will it be the same amount of time the second time around (with a pre-stretched chain)?

Uh, yeah, that's what I meant about the lack of any external indication that it needs to be replaced. Of course even if it did have an external indication a catastrophic failure wouldn't give much of a warning.

 

[ionbeam]

...that's what I meant about the lack of any external indication that it needs to be replaced. Of course even if it did have an external indication a catastrophic failure wouldn't give much of a warning.

You will start to hear rattling noises on the right side of the engine when the cam chain starts to loose tension. Most average riders are attentive enough to a change in 'normal' engine sounds to notice it. By putting a metal rod, screwdriver, etc on the right side of the engine then press your ear to the end of the probe you will clearly, plainly hear the cam chain noise. I'm not going to even try to put a spec on when the noise is starting to indicate failure... But, I will note that when the cam chain is good and the CCT is doing it's job there will be no rattling noise, just chain & gear noise. When you hear a rattling noise start it means the cam chain has worn a bit and the automatic tensioner is not automatically taking up the slack. IMO, at this point you should start to seek remedy, be it manually extending the CCT or replacing the CCT. If you choose to manually extend the CCT you are just covering for parts that are no longer performing as designed.

If you delay until the cam chain gets very noisy and then try to manually extend the CCT plunger even after it is already too weak to extend by itself you may experience what I did. Push the starter button, hear a ever so tiny, almost unnoticeable HIC from from the engine, then it will spin like mad with 0 psi of compression on all 4 cylinders. I only found out about the weak CCT plunger from doing the postmortem on my engine.

I don't want to be an alarmist and say at the very first, barely perceptible noise the CCT should be changed but you sure should start to monitor it. Again, if there is noise it is because the CCT is no longer doing its job; it is no longer automatically taking up chain slack. If a part isn't performing its job I would suggest that it is bad(?).

 

[charismaticmegafauna]

So it appears to me that the plunger is spring loaded and once you have the timing point aligned with the "C" you loosened the locknut and let the plunger move in on it's own until it bottomed on the guide inside the motor. Then retighen the locking nut...

The plunger can't move because of the locking nut.... and the tightness of the bolt on the plunger shaft.

Yep..., that's a pretty classic example of a 'factory' manual cam-chain tension adjuster (there are other styles, tho...).

The "C" mark is the place in the engine's rotation where the least backwards rotation is exerted on the cam-chain by the valves' springs pushing on the cam-lobes. Different spots for different engines -- but, in similar areas for similar style engines.

 

[Brodie]

I have some news on the manual cam chain tensioner front...

I sent my used tensioner in to American Performance Engineering ( APE ) to see if they make a manual tensioner that fits our bikes. I got a call today and the gentleman said they did not have anything, however, if I let them keep it they will build one for the FJR1300. I will get the first one.

He said it should be through their shop in about 2 or 3 weeks.




That's progress folks!


Brodie

 

[RadioHowie]

Put me down for #2. :yahoo:

 

[Zorlac]

Put me down for #2. :yahoo:

Yours will be the Latvian left handed thread version in pink powdercoat finish.
Great news Brodie, keep us posted !

Thanks.

 

[JuiceMcGoose]

There you go. All APE tensioners are the same price, $51.65. For that kind of change why mess with DIY?

 

[RadioHowie]

There you go. All APE tensioners are the same price, $51.65. For that kind of change why mess with DIY?

It gives you a sense of accomplishment?

 

[Bugnatr]

Dumb question here- What's the recommended mile point where CCT should be changed? Barring a premature failure or sounds from the right side.

 

[RadioHowie]

Dumb question here- What's the recommended mile point where CCT should be changed? Barring a premature failure or sounds from the right side.

There really is no MTBF for the CCT.....but for peace of mind....2nd valve adjust ~ 52K miles.

Fortunately, "premature failure" is at least foretold by noise from the chain case area. Don't ignore it.