CCT Paranoia and urban repair myths

[jambo]

A manual cam chain tensioner is certainly one way round the issue, but for most users they are the wrong choice. The reason they are used in highly tuned engines is to circumvent fears that the cam chain tensioners will back off under high loads.

But there's a trade off, you need to manually advance the tensioners at service intervals as the cam chain stretches slightly, or to put it another way, from the moment it's adjusted, each manual cam chain adjuster is "seized" in that position.

Just a thought,

Jambo

http://www.youtube.com/watch?v=uBb__oK4OcU

this is what it sounds like...


simplest solution is manual tensioner, you can buy them instead of making it yourself. very common problem on early cbr600's as well, i run my Hurricane with manual tensioner for 10 yrs and 60K (kms), never had a problem!

this site has manual tensioners, but i got one at local bike shop for $25 ($50 here)
http://www.streetandcomp.com/mcart/i...ain+Tensioners

How does one know how much tension to place on the chain guide though?

[jambo]

Is there a problem with the tensioners for SVs sticking? Yes
Are the earlier bikes most affected? Yes
Should you fit a manual tensioner? Possibly, but I'd really just try and get the existing ones moving again, it's less effort, potentially no-cost, and they automatically advance by the proper ammount when working normally.

However, it's down to you. The K3 tensioners fit in the 99-02 bikes and are different, somewhere after that the design changed again so it's not a part Suzuki was above improving. Me, I tend to try and keep standard parts working than splash cash on a deviced that requires me to guess the pressure, and manually advance it. But it's not a bad decision, I just don't like it to be listed as the only obvious fix, because there's the potential for over tensioning, under tensioning, mis-torquing the lock nut etc


Edit: Oh and lets not be forcing the engine to turn backwards to fix this, 3rd gear or not

Jambo

[Taipan]

Some very interesting replies and the vid tells me I dont have noisy CCTs. So I'll leave it for now but think I will lock them down later on. I've often heard people talk about this but never quite got what they were on about. Thanks everyone.

[yorkie_chris]

Originally Posted by jambo

there's the potential for
over tensioning,
under tensioning,
mis-torquing the lock nut etc


Edit: Oh and lets not be forcing the engine to turn backwards to fix this, 3rd gear or not

What were those first 3 again? Sounded a lot like "lunched engine, lunched engine and maybe a lunched engine" to me

The rolling it backwards thing is supposed to put the slack in the chain to the tensioner side of the chain, allowing it some slack to click out a notch or 2 more and shut the thing up. Whether it works or not is another question...

Isn't there also a worry that a locked off tensioner doesn't have any give, which could increase wear on the chain? Or is this simply another facet of the CCT bodge myth (something I've looked into, as I'm still considering a Firestorm as my next bike).

[Taipan]

Originally Posted by yorkie_chris

What were those first 3 again? Sounded a lot like "lunched engine, lunched engine and maybe a lunched engine" to me

The rolling it backwards thing is supposed to put the slack in the chain to the tensioner side of the chain, allowing it some slack to click out a notch or 2 more and shut the thing up. Whether it works or not is another question...

Funnily enough a guy on another forum I use did just this and it worked!

What causes CCT's to fail or become seized?

[jambo]

It's rare that CCTs fail. Generally they just get a little stuck. The ones used in the early SVs work by having a coiled spring attached to a threaded bolt. When you back the tensioner out (retract it) you are screwing this bolt in against the tension from a coiled spring, when you release it the spring unwinds, turning the bolt in the thread until it's unwound and extended. You'll see when you take one out, I fear I'm doing a bad job of explaining it.

The front tensioner especially tends not to get much oil so it can get stuck in it's thread. My SV has ~35,000 miles on it, but the engine's of unknown origin. I simply took the tensioners out when I was doing the valve clearances and made sure they were moving cleanly in the threads and made sure I put some oil through the mechanism. Seems happy so far.

Personally I prefer the ratchet type tensioners, where a spring sits behind a bar with a ratchet on it so it advances in a straight line, without the need to turn.

Jambo