CCT Operation

[Normanmeyers]

I have a 2004 with 70,000km.

On the good advise from this forum I have an APE cam chain tensioner in-hand. It is too cold in my unheated garage to get into it for a while but I am thinking about it.

I have not seen a stock FJR tensioner open so I do not know how they work. On my KLR, and others, there is a spring that pushes a ratcheting bar. Once it is advanced a click it cannot go back. On reading here it sounds like the FJR system uses a spring against the bar and the tension against the cam chain guide can float.

The APE is mechanical and will not give the system any "float".

My questions:

Is my reading of how the stock CCT works correct? And, does the FJR cam guide need to float Slightly?

Thanks,

Norm

 

[TomInPA]

Norm, you have the manual chain tensioner that Radiohowie installed in his bike. Most of us have used the updated OEM tensioner. You need to take some precautions when installing the new chain tensioner because simply removing the old one could allow enough slack in the cam chain to allow it to skip a tooth. Most of us change the tensioner during the valve clearance check. If you have not had one done, you're overdue.

FredW had an excellent thread here https://www.fjrforum.com/forum//index.php?showtopic=116778&&p=787762&&page=3&do=findComment&comment=787762 that shows how to shim the cam chain to prevent it from skipping as you pull the CCT. The OEM cam chain tensioner has a slotted screw that can be turned to withdraw tension and lock it. You just want to be sure the chain is secured before you do that.

I would actually recommend the new OEM CCT. By using that, you will know how the original one works. The new one uses a stronger spring and better construction to prevent the chain slack from forming. You should read this thread completely before starting. https://www.fjrforum.com/forum//index.php/topic/116778-gen1-cam-chain-tensioner-cct-replacement-lessons-learned/

 

[BkerChuck]

To echo what Tom said, the new OEM version seems to be a great improvement over the original iteration and the swap is pretty straight forward. I read up on most ot the CCT threads before changing mine and it appears many of the guys who went APE manual did so prior to Yamaha issuing the new updated version. It's my understanding the manual works very well but I guess I'm partial to having one less thing to have to adjust so the new green dot/blue dot version went into my personal bike.

 

[12tinker]

It appears that my '06 will have a old design tensioner? Wonder what year the new designs were installed? Just have 18K on her and probably not worry about it till 26K valve check or noise.

Prudent enough?

Just became second owner of this garage queen and doing as much pm as I should this winter like...

Spider check

TB sync

brake fluid flush

fork oil

PO already installed throttle tube, spring unwind and PC3

Great machine!

 

[eflyguy]

I'd be curious too, as my '08 isn't really close to needing a valve check @22k, but I might as well do it while I've got the tupperware removed. Lots of poorly-installed electricals to clean up, seems like a good time to take a look, and while I've got the cover off, the CCT would be trivial to replace. Peace of mind, and all that...

 

[TomInPA]

My recall is that the blue dot upgrade came out in 2008. Changing the CCT is not a hard job, but it is critical to protect against the chain going slack. Removal of the clutch cover to make some room, makes it much easier to turn the bolts and make the replacement. To my knowledge only the Gen I bikes ever had the CCT fail to the extent that the bike went out of time enough to grenade the engine. The manual calls for a valve clearance check at 26k miles and it is rare for there to be a need for shim adjustment at that first check.

 

[RossKean]

My recall is that the blue dot upgrade came out in 2008. Changing the CCT is not a hard job, but it is critical to protect against the chain going slack. Removal of the clutch cover to make some room, makes it much easier to turn the bolts and make the replacement. To my knowledge only the Gen I bikes ever had the CCT fail to the extent that the bike went out of time enough to grenade the engine. The manual calls for a valve clearance check at 26k miles and it is rare for there to be a need for shim adjustment at that first check.

Timing cover, not clutch cover...

May need to have a replacement gasket.

 

[TomInPA]

I actually pulled both the timing cover and clutch cover. It allowed enough room to swing the wrenches without cutting them down or any special tools. I think it's in that thread I lined above.

 

[RossKean]

I actually pulled both the timing cover and clutch cover. It allowed enough room to swing the wrenches without cutting them down or any special tools. I think it's in that thread I lined above.

Interesting. I didn't do that and while access was tight it was do-able. With any luck, I'll never have the opportunity to try it your way. My "Blue Dot" CCT had been running for the past 130,000 miles without any odd noises.

 

[lnewlf]

If you happen to have the cam cover off for a valve clearance check it is possible to reach a long thin screwdriver down the can chain tunnel and jam it tight against the slipper to maintain tension on the chain while changing the tensioner...

 

[wfooshee]

Whenever I worked on mine, either valve check (I had to remove one cam one time) or the CCT change, I zip-tied the chain to every sprocket before any disassembly, then released the tension. Chain's not going anywhere then....

 

[Brodie]

Norm

I am the one who prompted American Racing Products to make the manual cam chain tensioner for the Yamaha FJR. It was at a time when it seemed our bikes were in trouble of dropping like flies from the shortcomings of the original design tensioner. We already had several of our member's bikes with severe engine damage, and others reporting loud rattling sounds in the top end at idle. I had reciently purchased a used 2004 CBR that the previous owner installed an APE. It seems that that bike also has a history of timing chain tensioner failures. That got me looking toward them for a solution. They didn't have one for our bike, but were interested in adapting their design. I pointed them to several of the discussions on the FJRForum at the time, and sent in one of my old tensioners for them to evaluate. They saw an opportunity and agreed to make it.

I got the prototype unit and was the first one to run an APE on the FJR. That one had a nut welded on the outside end of the screw for adjusting with a wrench. I had to cut it off and hacksaw a screw driver slot in its place to get it to fit up because of it being such a tight fit next to the frame. The manufacturer made that adjustment to the design and put it on the market. The also sent me another one from the first production run as a thank you gift. I ran that one for over 120,000 miles on my first two '06 FJR bikes. The prototype went to our member in Florida, Radio Howie, who was just getting his bike back together after an engine swap due to a failed OEM tensioner. It's a good design that when properly adjusted will run for the life of the bike with minimal care. But every so often it will need to be readjusted to take up the slack from eventual wear of the timing chain system.

Here's the issue... If you're not careful, it can be set too tight and cause premature wear to the timing chain system. You also need to be careful when making that initial adjustment because you will be messing around with the chain slack while running the engine; and there is no exact spot where you know it is at the best adjustment, you will have to make a judgement call on that.

It's also a little messy with time. There is an O-ring under the lock nut, but oil will still weep past it - not much, but enough to get things oily dirty in that area.

I decided years ago that the revised design CCT, both blue dot and green dot tensioners have proven themselves. To my knowledge there has been no failures, and no reports of excessively noisy valve train when these are installed. On my current '08 AE I have the green dot installed and haven't looked back. In my mind it's a no brainer, get the updated Yamaha part and put it in as soon as you can and be done with it.

Brodie

 

[Normanmeyers]

Thank you Brodie.

Very helpful advice.

Norm

 

[Wm.P]

I have a 2008 with 65,000 miles. I just finished a valve adj. that went smooth thanks to all the great info I have found here. I'm pretty sure my CCT is begining to fail. Is the 2008 built with the updated CCT? Any wisdom from you all is greatly appreciated. Thanks and ride safe.

 

[RossKean]

I was under the impression that the newer design came in late 2007 or early 2008 model year. My '07 had the original design. Look for a blue dot on the CCT. If in doubt, replace it. Especially if you are gettng right side can of marbles sounds; particularly right after startup.

 

[escapefjrtist]

I have a 2008 with 65,000 miles. I just finished a valve adj. that went smooth thanks to all the great info I have found here. I'm pretty sure my CCT is begining to fail. Is the 2008 built with the updated CCT? Any wisdom from you all is greatly appreciated. Thanks and ride safe.

If you're starting to get noise from the RH side of the engine, blue dot or not replace the tensioner. Peace of mind for the small $$ cost is well worth it. Latest tensioner version has a green dot last time I had one in hand.

For reference, blue dot on left, old design from my previous '06 on right, both in fully retracted position.

--G

 

[FJR Flyer]

Brodie, how many miles do you have on the green dot CCT? Just wondering how far they have gone. I installed the blue dot CCT in '11 and currently have 60K miles on it. Its not making any noise.

 

[Normanmeyers]

Thank you again for the very enlightened discussion and information.

I have a manual (APE) unit in-hand but I will probably opt for the Yamaha green-dot as recommended.

Just for discussion:

It is now clear to me that the Yamaha design allows the chain to "float" a little bit to respond to varing tension on the cam chain during operation. Clearly, the APE manual design, and the ratcheting types that I am more familiar with, do not.

What is the engineering wisdom that would make Yamaha stay with the more complex "floating" design?

Thanks for your thoughts,

Norm

 

[Fred W]

Not really true. While the Yamaha CCT design does not have a positive ratcheting mechanism as is common on other designs, the pitch of the screw mechanism is intended to provide a "one-way" tensioner by design; it is only supposed to extend as the chain,sprocket and especially guides wear over time. It is not intended to retract in use.

You can feel this for yourself when you have one in hand: wind up the the tensioner you can hold it from extending with just your hand pressure on the ends. As you release pressure the tensioner will unwind internally and extend the plunger, and it is (supposed to be) impossible to push it back in from the ends

Because there is no ratchet to prevent it, if the internal spring torsion becomes inadequate, the tensioner may "back out" under some circumstances and that result in enough slack to skip more than one sprocket tooth, resulting in a catastrophic collision of the piston top(s) with still open valves as this is an "interference" valve design engine.

The later (paint dotted) versions of tensioner can be felt to have increased spring torsion over its entire range of motion as compared to the earlier ones, which helps reduce that possibility.