midijunky

But this one is different! :P

I'm taking on this project next week, just had a question about cam chain stretch. How can I tell if the chain is beyond it's service life? I've searched the forum but I must not be holding my mouth right.

cliby

looking through all the service manuals I locate, I could not find a specification for the service limit on the VTR cam chain. If it exists, honda wasn't making it obvious. People on the forum have good running engines with many miles so its probably not much of an issue and the chances of you being out of service limite would have to be very small: others can chime in if they've ever heard of one needing replacing. When I rebuilt mine I compared total chain length from an engine with 3K miles to one with 14K and couldn't measure a difference. If you wanted to be super-**** about it, you could degree the cams and set it to spec - that would allow for differences in tolerances and chain stretch and assure you valve timing is where it should be. I found mine was a couple degrees out of spec - which isn't trivial.

bill

midijunky

meh i'm cracking the case this summer to do some internal work so I may as well do it then. if it were that out of spec would I notice a difference in power?

Pretty much my only symptoms in this whole dealare an intermittent "rattle" I guess you could describe it as. It's intermittent in the sense that when I start it up, sometimes it rattles. halfway to work, sometimes not all the time, but it will stop making noise and all of a sudden the bike runs amazing. So at that point, I assume my CCT's are tensioning, and life is good, blah... and of course honda just tells me they have no clue how to check this. but he'll gladly sell me a new chain!

Regardless if the CCT's are to blame, I figure I should change them out for peace of mind?

cliby

the stock automatic ones (if functioning), can only get tighter - they don't tighten and loosen, only tighten as the chain stretches slightly. so your intermittent noise might be something else, or just the normal sounds of the v-twin engine and depending on engine temp and rpm you may just be hearing different aspects of it. A lot on this board have a healthy paranoia about the stock CCT's failing and therefore many have changed them for the APE manual CCTs. I suppose it depends on mileage - I personally intend on leaving the stock ones in.

midijunky

what else could it be? the noise follows rpm and is coming from my front cylinder head area. I can feel the vibration of the rattle against the side of the case. the noise is Very irregular, like a chain slapping or something, and when you blip the throttle a little bit and let off it'll give a louder rattle as it idles back down.

midijunky

I should add that the sound is definitely not a normal v-twin sound. It only started making the noise recently, about 7 months after I bought the bike. 18k miles on her.

any ideas, anyone?

Thumper

If functioning is the key words. It has been a known issue on several Honda sportbikes (VTR, CBR, etc) that the CCT fail or back out and then retighten.

I had the warrantee replacement Honda Auto-CCT installed and they were no better. I could at times hear the chain slapping at idle, power off the engine and start her back up and the tensioners would auto-adjust again.

Mine seemed to do it worse just after a hard deceleration.

I am APE now, so no more noise for me.....

midijunky

Ok that is EXACTLY what mine does. I can kill the engine, restart it, and then the noise is gone, only to come back in a short time. Thank you sir, APE's for me I guess

cliby

Its really hard to trouble shoot a noise without hearing it. And not to start/maintain an argument, but for the CCTs, I do not see how the design of the stock ones would ever allow "intermittent" failure and explain your intermittent noise: they just aren't designed that way. I could understand how they can completely fail, but not intermittently fail/work. I double check other things on your bike first.

Anyway, they are easy to replace: but I will say, I have read far more botched replacement stories resulting in bent valves on this site than actual failed CCT stories resulting in bent valves. So just be careful and don't skip steps.

bill

midijunky

that's the problem, I cant think of anything else that it could possibly be. Thumper had the same symptoms it looks like and switching to MCCT's fixed his intermittant slapping noise.

Is it possible the ACCT's could get clogged with crap from the engine? My oil gets very dirty very fast, I suppose it's sludge? Anyway I'm running rotella in it until it cleans up a bit. Anyway, I suppose the oil passages could get blocked, and then become unblocked. Possible?

Hawkrider

If the spring is weak or broken then the CCT CAN back out. It's not designed to with proper internal spring pressure. I think that part of the design flaw is that the stock CCT is not up to the pulsing of the V-twin, with the associated cam chain vibes.

midijunky

I appreciate the responses guys. This is the noise I've been chasing for the past couple months, at least now it's been narrowed down to what it is. guess she's parked for a week while I walk to work until parts come in

I guess the good news is she'll be running strong through the winter and I wont have to worry about it dying on me.

Greg do you know of a way to check cam chain stretch? or should I even worry about it at 18k miles.

Hawkrider

I wouldn't even worry about chain stretch. It's not like an old 350 chevy. It's a Honda, and you're only operating 4 valves per chain. We've had a few members ride over 100k hard miles and never an issue with that.

bkelsey

After taking the auto's apart after I changed to APEs I was wondering the same thing, but my experience with the intermittent noise and the tons of postings here are enough proof for me. When it started making noise, I changed them and it fixed the problem.

viperkillertt