What fails on a cct?

[Phil_H]

Hi all, infrequent poster alert...

I'm just wondering, what exactly fails on the auto tensioners when they ''let go''?

Cheers, Phil

[lloydie]

The spring in the cct brakes then the valves smash on the Piston and then the piston fragments go in the crank and feck that up too and gear box and new engine is needed in the worst case but if your a lotto winner no other damage then the spring

[bsabloke]

The muppet on the handlebars that doesn't act on all the information available

[AMCQ46]

As lloydie says...it's the little spring inside the CCT that fails.

With the spring in place, the lead screw in the CCT can't be pushed back inwards buy the cam chain forces, but when it fails the tensioner will move back inwards with vibration and chain forces. then the cam chain can jump on the sprockets and once the cam timing is out by more than 3 or 4 teeth all kinds of bad things will happen

[Watty]

The muppet on the handlebars that doesn't act on all the information available

[Phil_H]

Cheers guys.
I thought it was the spring that failed.
I sourced a used (working) cct for examination purposes and to see if there was any way of locking it therefore making it semi rather than fully automatic (yeah, I know it's been done to death!)

For the life of me, I couldn't understand how the cct backed off by itself. It's only possible with the spring removed (or failed) AND the plunger is jiggled.
My initial thoughts of bolt & locknut into the blanking stud hole to tighten onto the slot just won't work, however a grub screw into the side of it, would but this would require disassembly, drilling & tapping.....

I'd like to keep the auto adjustment (correct chain tension) rather than manuals but be able to lock it for safety. Best buy a new pair of tensioners methinks ;)

Cheers again, Phil

[Watty]

Cheers guys.
I thought it was the spring that failed.
I sourced a used (working) cct for examination purposes and to see if there was any way of locking it therefore making it semi rather than fully automatic (yeah, I know it's been done to death!)

For the life of me, I couldn't understand how the cct backed off by itself. It's only possible with the spring removed (or failed) AND the plunger is jiggled.
My initial thoughts of bolt & locknut into the blanking stud hole to tighten onto the slot just won't work, however a grub screw into the side of it, would but this would require disassembly, drilling & tapping.....

I'd like to keep the auto adjustment (correct chain tension) rather than manuals but be able to lock it for safety. Best buy a new pair of tensioners methinks ;)

Cheers again, Phil

Stopper mod

[bsabloke]

Posted on this forum.
A member took his new purchase to his local honda main dealer. New auto cct's fitted. Failed within 24 hours

How often do you think you will need to adjust manual cct?

[popkat]

Manuals will need adjusting very rarely, once you've set them up correctly they will be good for many miles.

I've done both stopper mod and manuals, stopper mod is good but if the spring fails you have to fit new ones twice, once to set them and again to do the mod, just takes a little longer. Manuals once fitted should not need removing again. Although stuff on here says you can do it all with only removing the rear cam cover I'd suggest removing the front one too it's not that difficult to get off, you can check the valve clearances while your in there too. Do make sure you line up the rotor correctly, there's a mark just before the T mark, some think this is the T mark, if set up this way the timing will be 1 tooth out, measure twice cut once and all that...

[bsabloke]

Well said popkat. How many times do you want to do stopper mod? Manuals once then sorted.
alternatively have a couple of spare heads, gaskets etc & hope your valves don't tomahawk the pistons on cct failure. Not fogetting a replacement cct when you fit those parts.

[AMCQ46]

if you want to keep the Auto part working, but have it failsafe, you have just described the stopper mod! have a read in the knowledgebase, all the development work has been done and it works.

only downside is that you might have to change the CCT if it fails, but once you did it once it is fairly easy to do [and I find that the same stopper size will work for the new CCT when you fit it ]

[Phil_H]

Lots of info
I hadn't realised that there was so much distrust in the oe tensioners!
I initially hopedcthat I could lock the tensioner without removal. Oh well!

I'll have a ponder and see if I should go down the manual tensioner or stopper route.

What a shame there isn't a lockable auto tensioner or a mod to the same effect.

Cheers, Phil

[AMCQ46]

What a shame there isn't a lockable auto tensioner or a mod to the same effect.

Cheers, Phil

phil,
the stopper mod is the same effect as a lockable auto tensioner.

if the tensioner doesn't fail, it will work for the rest of the bike life as a fully Auto tensioner. if [when] it fails the stopper will limit how far the CCT can retract, and this is set so it wont be so slack that the chain can jump the cam sprocket........ It will just make a lot more noise as the chain slaps about a bit

[Watty]

What a shame there isn't a lockable auto tensioner or a mod to the same effect.

Cheers, Phil

phil,
the stopper mod is the same effect as a lockable auto tensioner.

if the tensioner doesn't fail, it will work for the rest of the bike life as a fully Auto tensioner. if [when] it fails the stopper will limit how far the CCT can retract, and this is set so it wont be so slack that the chain can jump the cam sprocket........ It will just make a lot more noise as the chain slaps about a bit

Thats what I said earlier, but used less words

[AMCQ46]

Thats what I said earlier, but used less words

true........... Just not sure Phil is getting the message



STOPPER MOD






NOW