What's the OEM spec for replacing cam chain?

[Toecutter]

With all the tragic motor implosions of late, including one I know of with only 70k miles, as my own motor approaches 60k miles, I'm feeling anxious to get in there and check the status of the "critical link".

So, what does the factory say about replacement? Is there a freeplay measurement (I'd hope), or a time period in miles when replacement is recommended?

I'm really dubious about counting on the CC tensioner to keep enough slack out of the assembly to prevent a jumped tooth and the resulting catastrophic failure of the motor. Is a new chain slack enough to jump a tooth without a properly working CCT? If so, that's gonna incite some sleeplessness on my pillow....

 

[JuiceMcGoose]

According to my 1'st gen owners and shop manual, there is no mention of the cam chain tensioner or cam chain in periodic maintenance. As far as replacement the shop manual says the following:

1. Check:

• timing chain 1

Damage/stiffness → Replace the timing

chain and camshaft sprockets as a set.

So, basically, it says nothing.

If they are loosing it at 70K and you have 60K...well, you know what I am going to say...get in there and change the tensioner, chain and sprockets. Some may last 150K but in my book, if we know some are going out early best to be sure than sorry. Sleep better too.

 

[Patriot]

well, Scooter has never changed a chain

I believe the tensioner weakened enough to cause the problems...Ionbeam and I seem to agree the chain can whip enough when the key is turned off to kill engine to rise off the sprocket(s) and the engine reverse enough (1/4 turn?) for pistons to hit valves, or at least skip teeth. Then the chain can then go right back on the sprockets in or out of time. My chain is still on the lower sprocket in time.

So, my 1.5 cents is: check your tensioner more often than you think (but it's a subtle feel if enough tension)

In hind sight, if given we check out valves every 25k miles and 99% of the time the 25k check is fine, the at 50k, along with a valve check, I'd replace my CCT (you do know the part number has changed, but no-one seems to know what the change is).

If I need a valve adjustment, well then that requires pulling the cams, so I'd change the CCT and CHAIN.

Only extra work is to pull the ignition rotor off the crank end to get to the chain/sprocket on the crank.

If I changed the CCT at 40k or 50k miles, I'd be sure to change it again at 80-90k, or every time the valves needed adjustment when I'd change both the CCT and CHAIN.

Some may want to be more anal and change the CCT every time the valves are checked. The CCT and gasket from Mondak cost $63 and it took me less than an hour to change it with the proper tools.

 

[Patriot]

there was a movement to look into a manual cam chain tensioner from a prominent company who made them for other bikes. I believe the idea was to send them a used one and see if they had something already that would work or make us one for the FJR that they could sell at a profit.

I haven't heard anymore about it for months and my memory sucks these days and can't remember or find the thread.

 

[Fred W]

There was also someone who converted an automatic CCT to manually adjusted one. I still only have 30k miles, but that may be the route that I pursue. I've never heard of a chain breaking. I've heard of too many auto CCTs allowing a chain to skip and screw the pooch.

One added note: The automatic CCT on my Hinkley Triumph Trophy is exactly like an automotive tensioner design. It has a longitudinally compressed spring and a ratcheting pawl, anti-reverse feature.

They don't talk about damaged valves and timing chains skipping on the TriumphRat.com web site.

Coincidence? I think not.

 

[Patriot]

to squash the mass histeria, we are all in agreement this has reared it's ugly head only on Gen I 's ??? Am I right ???

 

[Fred W]

to squash the mass histeria, we are all in agreement this has reared it's ugly head only on Gen I 's ??? Am I right ???

Only because they are older.

The CCT design is essentially the same so there is nothing that exempts the 2nd Gens from joining in the fun a few years down the road.

That said, I was contacted by a fellow board member today who described symptoms that sounded eerily familiar to a slack cam chain noise (not yet out to lunch). Marbles in a can sound that diminishes some as the engine warms up.

His is a 2006.

 

[FJRay]

There was also someone who converted an automatic CCT to manually adjusted one. I still only have 30k miles, but that may be the route that I pursue. I've never heard of a chain breaking. I've heard of too many auto CCTs allowing a chain to skip and screw the pooch.
One added note: The automatic CCT on my Hinkley Triumph Trophy is exactly like an automotive tensioner design. It has a longitudinally compressed spring and a ratcheting pawl, anti-reverse feature.

They don't talk about damaged valves and timing chains skipping on the TriumphRat.com web site.

Coincidence? I think not.

I converted one of my old ones to manual. I haven't installed it yet as the one in the engine only has about 12k on it. I will probably switch at the next valve adj. It is a easy conversion if you have access to a lathe. I may still have some pidtures if somebody wants them or I will take some more.

The ratcheting type is far superior.

 

[Toecutter]

If the FSM and owner's manuals say what nothing, and some have had CCT's changed under YES (I did at about 48k), then how is this not another warranty issue like the tick? RH et al should maybe not have to bear the cost of repairs if they've adhered to the recommended service schedule, especially if a dealer's service records documents the adherence.

Is it time to start another battle with the mothership?

The ratcheting type is far superior.

I can't imagine a chain getting loose enough to cause any problems if the tensioner couldn't back off any. It would probably have to get stiff and break first. Isn't the tensioner backing off what's causing these disasters? If so,

Is it time to start another battle with the mothership?

 

[Fred W]

Oh, self quoting. I hear that's the first sign of mental infirmity...

But yes, I agree. I think CCTs backing off on tension is the problem. The chains do not wear enough, fast enough to allow chains to skip teeth on the sprockets.

As to going after Yamamaha...

If you are out of warranty, and not covered by YES, I'd have to say you are S.O.L.

 

[Toecutter]

If you are out of warranty, and not covered by YES, I'd have to say you are S.O.L.

They've fixed tickers in the same status....

 

[JuiceMcGoose]

My FJR has 8,600 miles so I won't be getting in there soon but if someone wants to send me their old CCT I will take dimensions, make a sketch and send it out to what ever suppliers I can find, or you can think of, for a ratcheting CCT. As long as it ratchets I don't see a problem with the autos. Maybe something there I don't know.

 

[FJRay]

My FJR has 8,600 miles so I won't be getting in there soon but if someone wants to send me their old CCT I will take dimensions, make a sketch and send it out to what ever suppliers I can find, or you can think of, for a ratcheting CCT. As long as it ratchets I don't see a problem with the autos. Maybe something there I don't know.

Most of the ratcheting types I have seen are longer than the one on the FJR and there isn't a hell of a lot of room. If one would fit it would be cool.

I won't know for a while how often the manual one I built will need to be adjusted but it has a compression spring in it so I don't think it will need much attention.

 

[RadioHowie]

With all the tragic motor implosions of late, including one I know of with only 70k miles, as my own motor approaches 60k miles, I'm feeling anxious to get in there and check the status of the "critical link".
So, what does the factory say about replacement?

Only if it's "stiff". I'd guess that means if it's kinked. Or the camshaft sprockets indicate wear.

Is there a freeplay measurement (I'd hope), or a time period in miles when replacement is recommended?

The whole concept of a cam chain tensioner is that there is NO freeplay measurement. Theoretically, the chain is always tight.

I'm really dubious about counting on the CC tensioner to keep enough slack out of the assembly to prevent a jumped tooth and the resulting catastrophic failure of the motor.

Yeah...me too.

Is a new chain slack enough to jump a tooth without a properly working CCT? If so, that's gonna incite some sleeplessness on my pillow....

Absolutely yes, a brand new chain could go AWOL if the CCT isn't up to the task. Based on the premise that a cam chain doesn't really stretch, it only wears, then a 100K miles cam chain would be the same length as a 0 mile chain. The CCT takes up slack in the chain brought on by wear in the chain rollers and sprockets. That's why MamaYama recommends camshaft sprockets be replaced as a set with a new chain. Fergit changing the crank sprocket. It's pressed on with about 10 million PSI and if it's bad, you're buyin' a new crank

 

[cota95]

to squash the mass histeria, we are all in agreement this has reared it's ugly head only on Gen I 's ??? Am I right ???

Only because they are older.

The CCT design is essentially the same so there is nothing that exempts the 2nd Gens from joining in the fun a few years down the road.

That said, I was contacted by a fellow board member today who described symptoms that sounded eerily familiar to a slack cam chain noise (not yet out to lunch). Marbles in a can sound that diminishes some as the engine warms up.

His is a 2006.

His bike only has 22k on it but is still under YES

 

[JuiceMcGoose]

Who said cam chains don't stretch?

 

[Patriot]

Who said cam chains don't stretch?

have ya ever seen a Feejer cam chain ???

don't compare it to the drive chain on a R1

 

[wfooshee]

"Stretch" is used to indicate an increasing distance between where the sprocket teeth seat themselves on the chain. The chain itself does not stretch, as RH points out. The pin-to-pin distance never changes. But as the rollers wear, the distance from where the chain sits on the crank sprocket to where it sits on the cam sprocket does actually increase, and that's "stretch." The chain isn't any longer overall, but the space between links is, because the inside surfaces wear down.

Chains don't stretch, but we call it that.

 

[user 213]

Talk about a quote fest!

I don't think anyone has had a cam chain wear or stretch, despite a couple having been replace under warranty. FWIW, I've had 3 CCTs replaced under the YES, the last one at 89k on the motor that was denied repair due to ring wear. They checked my chain and sprockets at one point during the diagnosis process on the low compression issue. No problems with the chain at all, (and they are cheap, so I don't think they would have hesitated to replace it).