Bngt

Thank you!
I believe the conversion has already been done and proposed by others. With a screw and locknut instead of the adjusters internals pushing on the plunger.

autoteach

well, I had a 650 burgman with a failed tensioner this last summer. The mileage was low, and the failure was a result of the cam chain guide getting pounded out of shape and causing a torque on the tensioner arm, thereby pressing the roll pin back in the body (roll pin used to keep teeth aligned with ratchet mechanism) and allowing the tensioner to move in and out unabated. Will it fail again? IDK

Bngt

I had a look again at the picture of the disassembled CCT. Maybe it is possible to just put a pin of the correct length inside the plunger to limit the travel to 1-2mm. That would then prevent the plunger from retracting dangerously far and still allow the spring to do its job.

Objections?

ripvanwinkle

Some of us here in the UK have been doing just that for a good number of years now. The beauty of doing this takes away the guess work in setting the correct tension when using manual tensioners such as Ape, but still gives peace of mind if/when a failure occurs. It also means the standard cam chain tensioner can work as Mr Honda intended. Both the front and rear CCT's tension change as the rev's increase.

Have a look at this link for more and the 4th post up from the bottom:-
http://www.haymouth.co.uk/phpBB3/vie...=3179&start=60

Bngt

Jippeee!!!
I knew it. There had to be a smart and simple solution. I wouldn't want to run fixed tensioners as they then can not manage the heat variations and especially now that I read that the rear one slackens when the front one tightens at rpm.
Thank you very much ripvanwinkle.

Bngt

Tweety

Ok, I like the idea of that pin... It's a good solution...

But let's get this straight, since you are threading on very dangerous ice here... That little off hand comment might make whole new rumour mill of false assumptions around here...

The tension most definetly does NOT change as revs increase... By saying that you prove once and for all that you either have no clue as to what's going in in the engine, or that you are lazy and phrased that incorrectly, which is what I prefer to belive...

What is true is that the two CCT's are affected differently since they are positioned on opposite ends of the block, based on the rotation of the chains...

Also true that when moving from stationary to moving, the rotational forces start affecting the chain, as well as the known fact that avery chain loop has one tensioned leg and one looser "return" leg... So yeah, look at that isolated part of the system and you are correct, the tension changes with RPM... But if you allow it to do so, you get fun, fun, fun... Blown engine... Look at the whole system to see why...

The reason for the CCT's are to keep that tension constant or near constant... The springs in the OEM one's doesn't have anything to do with that percieved change, they are there to take up the chain lash from the transitioning from stationary to moving, and to allow the CCT to move enough to adjust itself... Basic physics say that the spring is incapable of doing what your statement says, as it would do the opposite of what you would want... More RPM's means more force, means more compressed spring, which means looser chain... Not good...

Tweety

Oh, not trying to convince anyone of doing a choice either way... But if you keep using "guesswork" when referencing manual CCT's, I'll get really pissed of... You migth be guessing... I'm not...

You have talked high and mighty about "scientific" this and that... And I have provided unbiased information, saying what can and cannot be done, and what facts I have... You might not have gotten the replies you wanted, but that's another matter... Then a better solution was presented... Good, I like that...

You set a manual tensioner to be quiet by ear when the engine is at operating temperature... That's not guessing, that's one of the most sensitive measuring devices ever constructed... And by doing that you leave out any temperature shifts, so put that myth in the same trashcan... I'm not sure what your background is, but mine is such that I can calculate the temperature shifts... And I can tell you without question that the sping induced movement in the OEM CCT's cause larger tolerances than the temperature induced changes ever will...

So if you want to use words as unbiased and scientific, well... Try to be unbiased about the side you dislike too, not just the side you prefer...

Looking at this without bias, the manual CCT's are without question better than the OEM one's... If you even try to argue against that I will cease to have a conversation with you... Period... And no, I'm not kidding... And no, this isn't a case of me being pissed of that you would prefer a non-manual CCT when I have promoted that... It's about fair and unbiased science...

Now, with the "pin-solution" applied to the OEM one's they are significantly better than before... But the springs are still producing larger tolerance shifts than the temperature does in the manual one's (and if this actually increases wear or decreases it, is something that would have to be tested to get a conclusive answer, not guessed at)... And with a chain that wears, the pin should ideally be growing over time, ie be replaced at intervalls... Making it as far as I can tell about equal to the manual CCT in terms of safety, wear and maintainance...

So while it's now safe from destructive failure, I still prefer the manual as my solution... Not a choiche made based on specific merits, but based on laziness, as I already have those installed...

Tweety

Just to clarify since the above might come of as just negative... I like the pin solution... I like it a lot... If I hadn't already solved my CCT problem permanently I'd probably put that at the top of my list...

Bngt

Tweety, don't be pissed. Be happy that we were able to figure out a solution to retain auto adjustment and still prevent consequences of a spring failure. I think it is quite remarkable that we did, considering that we have no clue about what goes on in an engine!

autoteach

I would like to weigh in. I could give a **** about what y'all like. The manual is a better option, period. The auto cct will fail, and pinned or not, you will have to replace it nonetheless. That is why the manual IS the better choice. If adjusted while warm, they will be the correct tension when warm, and slightly looser while cold. This may sound like a down fall, but I assure you it is not. When the failure rate on auto ccts are this high, across the entire product line (yes, once again, this is not the first cct that honda has failures with, it is one of the first engines that honda built that can skip timing with a loose cct). trx's, cbr's, vtr's, vfr's, etc.

If you neglect the facts, then it would seem that the ccts you think are better will be the ones you install. quit dicking around and pitch them into a furnace and melt them into something worthwhile. I know that I provided a solution for all as to how you could maintain the auto adjust, but I cant see it as a worthwhile time expenditure at all, especially with the failure rate (having dick and ***** to do with the year) and having more to do with the miles/time/"work" that they do. Do you want them to stop failing, pull them out and put in manual ccts. You will never have a failure again. Do you want another method of limiting the travel, well here you go: measure distance from sealing surface of plug bolt to the plunger at full height and then at full depth when installed. Get a bolt that is almost all the way down to the top of the "screw" portion of the cct. You may have to reduce the dia. to fit all the way down in the hole. Put bolt in, if cct fails, it will now hit the pin section of the plug bolt. There you go, another bandaid on a piece of ****.

ripvanwinkle

Right first of all just to put the record straight I'm sirch345 on the vtr1000.org site, which I did point out in my first post when joining this site.

Now back to the CCT's. I've put in more hours than I care to admit in R&D on the Firestorm CCT's to come up with this stopper/pin idea. So unless the Superhawk CCT's operate different than the Firestorm CCT's, I can definitely confirm the tension does alter with changes in the rev's. The way I did this was to make a device that shows from the outside of the CCT body what happens to the tension when the bike is being ridden.

Once I did that I could then mount a video camera on the bike to film what was happening.

You were right about one thing though, the rear CCT does operate in the opposite direction to the front.

What I found was this, at approximately 3,000 rev's the front CCT backs off the tension by approximately a quarter of a turn, it stays there in that position as the rev's increase. Once the rev's drop back down to approx 3,000 rev's the CCT tightens itself back up again.

The rear CCT at approximately 3,000 rev's (unlike the front tensioner) increases the tension on the cam chain.

I'm not suggesting using this method over fixed tensioners or any other modification to the standard CCT's, all I was doing was answering a question posted by another member.

I didn't feel it was necessary to go into great detail about the changes with rev's as that was not the question, but I felt it was right to point it out, as it's one of the advantages over manual tensioners.

Bngt, you're very welcome,

Chris.

autoteach

The slack in the chain should never be moved to any other side of the chain other than the tensioner side. This is critical, in all timing applications. If this is happening, there is a problem. And this problem is the auto ccts. They are NOT supposed to ever back up, bot on the moon, not in equador, not in australia. This is why they fail. They should turn in until correct tension is set, and when pressure is placed back on the tensioner, it should jam due to the high helix screw in its design. PERIOD. if it is moving in the negative tension direction, it is not working properly.

Tweety

Heh... Sorry for poking you with a stick then... I kind of assumed the part about the forum names but didn't know for sure... BTW I like detail... I also like discussions... That's what get us somewhere...

I honestly didn't know you had done that extensive research... Impressive to say the least...

The thing is, that description makes me cringe... I don't doubt that it's what it is doing... But it certainly isn't what it's supposed to be doing as far as my understanding on how this works... I know a fair deal about it, but others might know more, so if anyone can give a good explanation or argument for why it should, please enlighten me...

The thing is, the CCT's are for whatever reason mounted one on the pulling leg and one one the return leg of respective chains... (Because of orientation on the block and rotation of the chains)... That's why they behave like that... The tension on the chain chain changes from the rotational forces and the pulling forces, and the autoadjustable CCT's adjust themselves... I can see no benefit from this...

The end result is you will get uneven wear, as the chain will without any doubt have different tension on the two cylinders, with the tensioner doing different things defined on where in the chain loop it's positioned... Also it should mean excessive wear since the chain is allowed to lash more or less than optimally...

As autoteach said, they should adjust to correct tension, and hold steady when pressure is applied... And that is also part of the reason for the spring... That introduces enough "give" for it to function, and not be too tigth with the screw stationary...

I fully agree with autoteach... The auto CCT's should never back out... Never ever... Not for any reason... So I'll change my position... I'll stick with the manuals without second guessing that...

autoteach

and, on the vtr, along with every vehicle I know, has the tensioner on the slack side. ABSOLUTELY no questions. Our crank rotates forward, and both ccts are mounted to provide this tensioning by being located on the back of each cylinder, although they are mounted on opposite sides of the bike and opposite sides of the cylinder heads. There is a significant amount of torque required to operate cams, and there is NO way that a tensioner would hold up to this. If you have any questions regarding this, please spend some time speaking to someone who has owned or worked on a nighthawk 700sc with an understanding of the starter/stator chain failure mode.

I hope that my statements, while firm, are not taken as a personal attack. They should be taken as an assault on wrong assumptions, and illogical thinking. If you take some time to look at some vehicles, more than one model in particular, you will see this. No matter the rotation, the tensioner is put on the slack side. Look at your bicycle. Look where the derailur/tensioner is placed and try putting any torque in it in reverse.

Tweety

Hmm... That means some of what I said was incorrect as well, and thinking about it I really should have known the CCT was on the slack side... That means it's even more of a problem that the CCT's behave like they do, since they are both on the return leg, they should in all theoretical scenarios I can think of work the same, and yet they do not... Hmm... 'scuse me while I go stare at the parts fische for a while...

RWhisen

Class is over Autoteach?

autoteach

That's a good boy!

autoteach

Yeah, I will leave this as a lesson finished.

7moore7

+1. Speaking for myself, this clarified more than it should have