storm_rider

Never had a problem with mine. At 57,000 miles I decided to change these out with new ones after I set the valve clearances, just in case these have weakened somehow over the years.

Seems if you run the engine at high rpm under full throttle and suddenly snap the throttle shut (as you might while racing to negotiate an approaching sharp turn) I've heard there could be enough force developed in the cam chains to back out the tensioner lifters.

Apparently the VTR isn't the only machine to have this potential problem (also happens to the CBR 600).

Manual cam chain tensioner lifters are a good idea on race bikes.

ProfChaos

Apparently in response to complaints related to engine failure, Honda eventually upgraded the initial cam chain tensioner ("tensioner lifter assembly") to the following part number which super-cedes the earlier version: https://www.partzilla.com/product/ho...0e1b7e71d493eb

A local Honda Parts Manager told me that Honda switched vendors for the tensioner (lifter assembly), and the gasket is different as well, to fit the new housing.

If you plan on installing modified cams or plan on modifying the valve-train in any way to improve performance, I would say that you might be better-off not to use manual CCT's at all, just to be safe. Manual CCT's can be a bit tricky to adjust with tricked-out engines and might actually end-up being more trouble than you can imagine. For track bikes that are torn-down regularly anyway, it might not be that big of a deal to install manual CCT's, but with a bike that hasn't shown any signs of failure or cam-chain rattle, I would leave it alone and use the money for a nice exhaust, a light-weight lithium-ion battery, or something more practical, like a Sargent custom seat.

That's just me, and I am writing this response after having had a manual CCT possibly contribute to a bent titanium valve on an engine with very aggressive aftermarket cams (in a freshly-rebuilt 30,000-mile-engine that I purchased on eBay). It seems that the cam chains were stretched (because the owner of the bike from which the engine was taken apparently had a penchant for doing wheelies). Having automatic cam-chain-tensioners installed would have compensated to some degree for the stretched cam-chains, by applying spring-loaded pressure, whereas with manual CCT's the engine jumped timing and might have bent an expensive titanium valve. I will know the extent of the damage for sure next week, after my mechanic performs a compression test, but let me caution you anyway that just because other people have experienced CCT-failure, it does not necessarily meant that you will too. In my case, I might have been much better-off to have installed the upgraded automatic CCT's. All I know at this point is that--at a minimum--I have to install new cam-chains, new automatic tensioners and gaskets, and I might even have to request that Ferrea make me another intake valve, depending upon compression readings gathered next week during further analysis by a very reputable mechanic. (I wish now that the mechanic had told me in advance about his misgivings regarding installation of manual CCT's in tricked-out engines: It might have saved a little heartache.)

I hope that my little cautionary tale might serve someone well.

cheers,
--Professor Chaos

8541Hawk

I've taken both versions of the ACCTs apart and there is no visual difference. With that we can go to the, Is it just a bad design or are folks doing something to cause the issue?
They fail due to the spring breaking. How do you get a piece of tempered spring steel to break? The easiest way is to do something that damages the temper. Usually this is caused by excessive heat cycling.

So how does the end user cause an issue with the spring temper? They let it sit and "warm up" on the side stand.
If you look at the water table while the bike is leaned over along with how the cooling system works with the thermostat closed (which means the carb heat lines are flowing) you will see that it is very easy for the front cyl to overheat.
Then the thermostat opens and you flash cool every thing. Lots of heat and fast cooling.....what does that do to a bit of tempered steel?
Why the front and not the back? Because the rear one is full of oil. No it doesn't lube anything, it is a heat sink and causes the temperature changes to happen much slower.

With all that I also have never heard of a properly adjusted MCCT causing an issue.

So run whichever makes you sleep the best at night. Just do yourself and the bike a favor and stand it up before you start it. There is no need for a long warm up no matter how cold out. That is from the old air cooled days.
Letting it sit and "warm up" on the side stand is not doing your engine a favor. also on a new to you engine, replace the CCTs right away if it is fitted with ACCTs as you have no idea what the user before you has done which is also why you should check a MCCT before running a new to you engine again because you don't know what others have done.

fabiostar

honda never upgraded them. they changed to colour of the paint dots but thats only a batch marking...

number of standard cct blow ups.......dozens that i know of.

number manual cct blow ups............im still waiting to see one..

you can make your mind up from that.

E.Marquez

Every failed ACCT I have seen is due to broken spring.
Springs have a service life under the best working conditions, X number of cycles and the spring will fracture and fail. The spring will work harden and fracture.
Add in surface rust from long periods of storage and big temp swings/ humid air..and that service life can go down.
Add in something that cause the spring to cycle more often then "normal" (perhaps the issue with long decel?) and it will work harden faster and fail faster.

It was mentioned that heat may be a factor.. I cant say its not, no research...I can say in general, the temp it would take to make spring steel brittle and then fracture is a lot hotter then the rest of the motor would handle I believe, So im just not thinking heat is a factor ..It might be,..no way i can say its not..... but if the engine was getting that hot, valve springs should be failing as well, engine overheating, pistons seizing as well. Out of curiosity, I went and let the two VTRs I have in the shop today, mine and a customers idle till fully warm, with no air flow over the engine, coolant temps fully hot...the front CCT was no hotter than anyplace else on the head other than right near the header flange. I was wondering if the front CCT was getting heated by the header, but it seems not in the two I just tried that on and measured with moth an IR temp gun and contact fluke temperature probe.
If your bored try reading chapter 14 "Elevated temperature failures" in "Understanding How Components Fail, 3rd Edition"
and from a coil spring manufacture That was reference vehicle coil springs and may or may not apply to the type of steel used in the CCT coil spring

Point of all that....end of the day, the coil spring in the CCT has a service life...X number of cycles before the spring fails. How many? no idea, according to the OEM, there is no maintenance time frame or service interval for the CCT. implying it shod last the "life" of the motor, which...lol is kind of true, the motors life ends when the CCT fails.

8541Hawk

The first question would be did you warm them up on the side-stand? Second would be did you monitor the temp while it was warming up or only after the thermostat opened?
Heat is the answer and there is an explanation and I would be happy to explain more if anyone is interested. There is also an answer to why the front is the one that usually fails.

It is all down to how the cooling system works, the water table and how "warming up" the bike on the side stand is the root cause. Also why even with MCCTs it is not good for your engine.

Now many say it is just a poor design which can fail at any time, to which I have to ask , why would someone like Roger D put them in all the VTR engines he built? Wouldn't he know if the design was faulty?
Also if they are so prone to failure for no reason, why would he send his own son out on the track with them?

Wolverine

I would like to ask if you realize you dug up an 8 year old question and are currently answering it?

E.Marquez

He is mistaken, Ive inspected, disassembled and measured ACCTs from a VTR built Jun 1997,, 2000, 2002, 2004, and a brand new one bought as a service replacement Dec 2017, confirmed it was sent in form the US distributer warehouse, to regional distro to selling dealer... So not NOS that had been on a shelf for years.
There is NO change in design..Source vender ? Sure, new PN yup, but the ACCT itself never changed in design that can be seen or measured obviously.

The cam profile, or valve type is completely non relative to the choice of CCT.. At to keeping the chains tensioned properly.

skifreak

So, a possibly stupid question.

It seems to me that a properly functioning ACCT would apply correct spring pressure and therefore, correct tension on the cam chain in most all conditions, allowing for variables like sudden deceleration, cam chain stretch given time and heat, etc. In other words, if the ACCT is doing it's job, it adjusts to conditions appropriately. However, a MCCT applies only a given, set tension regardless of variables like sudden decel, heat, time, etc.

My question is, how often do you need to adjust the tension on a MCCT to keep it functioning appropriately? And, are they easy enough to reach that it can be done with a minimal of bike teardown to ease maintenance and eliminate proctastination? I imagine that an improperly adjusted or neglected MCCT would be just as injurious as a failing ACCT. I want to replace mine, but not sure how often to check them.

Also, what brand is the MCCT of choice?

Wicky

"I imagine that an improperly adjusted or neglected MCCT would be just as injurious as a failing ACCT. I want to replace mine"

Re Manual. If too loose it will rattle, if too tight it will cause cams to squeal. It would be hard, nigh on impossible, unless very uncorrectly fitted in the first place to have a manual become loose enough to allow the cam chain to hop, skip or jump.

For peace of mind adjust at the same time as getting valves checked.

Depends where you are - Kreiger, APE, Bazza and Ade Whitmarsh's CCT's - VTR1000.ORG

Krieger is based in sunny USA > Krieger Cam Chain Tensioners or there are APEs

E.Marquez

Actual use would indicate your concerns are not popping up as you theorize they might.

There is no need to tension the chain, the CCT is there to remove the excess slop, The MCCT once installed correctly is doing just that... In theory, it might need adjustment again as the chain, sprockets and chain guides wear, in reality Ive not had to readjust in 36,000 miles on one SH, and 22,000 miles on my other... Nor the dozen of SH and tens of dozens of other models I've installed manual CCTs on.

Where to get um? Well you can have um very cheaply on ebay, and hope they work out, you can get them moderately priced from Kreiger, APE, Bazza and Ade Whitmarsh's CCT's - VTR1000.ORG and know your getting a great product..I have these on one of my SH now. Or you can get them from APE and have the same thing as Kreiger's known quality...but at a bit more price for the design and trickery APE has put in them....are the APR's better for the money? Probably not in this application, but they are a nice bit of kit.. https://www.superhawkforum.com/forum...1&d=1517407117

skifreak

Thanks for the info. I plan on swapping mine out since my bike still has the ACCT (not sure if they are original or have been replaced), and at their age, although currently working, I am not betting the life of my engine and valvetrain on them. I love the bike too much. Think I will order up some APE Pros or Kriegers

Of course, the real cure is that Honda should have fitted the VTR with gear driven cams. Oh the mechanical music...

Samichman93

Auto CCT

In the link you attached, is that price for one or 2 i was unable to figure it out on the site.

Thanks
Samichman93

VTR1000F

One.

Wolverine

Taken my arms, taken my legs. Left me with life in helllllllahhh!

VTR1000F

You millennials, I just don't understand ya.

Wolverine

Lol. Wish I was still that young.

camchaintensioner

Incredibly important do it asap and do not start/ride it until you perform the CCT replacement. Do not be like me, my motor is likely toast.

fabiostar

Change them. yesterday if possible.
mileage...not important
honda updated them? complete bollox.
red dots are better than yellow dot accts?. again bollox.

99% of dead vtr engines are caused by????? accts.

killer5280

It's not toast, but it is going to require some work.

camchaintensioner

Your optimism is greatly appreciated, it is being worked on now!