Honda CBR XX Forum banner

1 - 20 of 36 Posts

·
Registered
Joined
·
543 Posts
Discussion Starter #1
Finally got sick of the clacking sound at idle and decided to do something with the factory CCT. Upon removing the CCT it became evident that there was still some automatic adjustment travel and I decided to figure out why the tensioner was not adjusting out further. I reassebled the CCT without the spring and blanking bolt and manually adjusted the tension with a screw driver. This was when I found an impacting type of force that actually encourages the acme threaded adjuster to turn clockwise and loosen its self. The factory spring is strong enough to work against it until the adjuster has travelled out about 15mms. The design of the spring won't allow it to be preloaded much more than factory. In all honesty it is quite a poor bit of engineering. As such I have devised a relatively easy way to convert it to a manual setup. Fortunately the bore of the CCT body has a smooth bore and thus lends its self to this intended mod. I will machine the simple sleeve in the lathe tomorrow and post some pictures of the modification and include the specifications. If it works out as planned, any machine shop should be able to knock up the sleeve that is used in conjunction with most of the original bits for about 10 to 20 dollars. Would be interested to know what is different in the newer CCTs. My guess would be that the spring is heavier. I will get back to you with the results tomorrow. HAVE A BLAST! Paul.:)
 

·
Registered
Joined
·
1,832 Posts
To me there are 2 options

1.Either you stay automatic C.C.T let it do its own job and have him checked/replaced every 30.000 kms

2.Go manual and be more anxious and nervous having to check it every 5-7.000 kms to compensate for wear/free play etc.
 

·
Registered
Joined
·
543 Posts
Discussion Starter #3 (Edited)
Yeah, Thanks for the link but he is not on the mark with his idea. A 6mm bolt will eventually push the guts of the unit in towards the camchain and the head of the unit will come out of a locating recess. I will post pictures of my completed mod. The only down side will be a simple manual adjustment every 5000kms or so. It amazes me that a motor as well designed as the bird's has this design of tensioner. Makes you wonder how it lasts as long as it does. He is right about the forces applied to the unit when running wanting to loosen the tensioner. It is only the initial spring tension preventing this from happening. Once this tension is lost as the tensioner travels about 15mms and the constant heating and cooling weakens the spring, the tensioner fails to travel out any further. Even though their is still another 10 mms travel left in the unit. HAVE A BLAST! Paul.
 

·
Registered
Joined
·
543 Posts
Discussion Starter #4 (Edited)
To me there are 2 options

1.Either you stay automatic C.C.T let it do its own job and have him checked/replaced every 30.000 kms

2.Go manual and be more anxious and nervous having to check it every 5-7.000 kms to compensate for wear/free play etc.
Unless there is something radically different with the new tensioners, routinely replacing them will ,IMO, only be a temporary fix. Unless they have a much better spring arrangement they simply will not exert enough force against the rear tensioner blade for the entire length of the tensioners travel. Honda obviously incorporated that much travel into the unit to ensure a long service life out of the chain and guides but the spring design simply won't apply sufficient force on the unit over it's potential range of stroke.The standard CCT potentially has about 23mms of stroke but the spring won't allow it to achieve that. When you take into consideration that a good few mms of travel would be lost with the initial lengthening of the chain and running in of the guides and sprockets, the original spring probably only exerted sufficient pressure for about 10mm of effective travel. That being the case the quality of the chain and guides must be first class. As far as being nervous about manual adjustment, don't be. When you notice the slight noise developing at idle when the engine is hot, simply screw the adjuster bolt in a turn and lock it off. HAVE A BLAST! Paul.
 

·
Registered
Joined
·
14,013 Posts
:popcorn:
 

·
Registered
Joined
·
543 Posts
Discussion Starter #7
G'day again, I have just completed the mod to the factory CCT to convert it to manual adjustment and it works absolutely fine. Later when my daughter arrives home I will post pictures of the mod as I have not got any idea of how you do it. Anybody who wants to do this mod will need to have a small sleeve machined up out of brass or mild steel. It needs to be 23mms long, 18.12mms outside diameter and have an 8mm hole bored all the way through it. I also machined 2 small grooves on the outside of this sleeve to take 2 o-rings. The original acme threaded device in the adjuster also has a couple of small mods done to it so as it effectively becomes the locking bolt for the mod. I will explain these mods once I post the pictures. 2 of the original parts are no longer used. They are the thin walled metal sleeve and the tensioning spring. In response to a couple of previous posts, firstly do not attempt the mod in the link provided earlier in this thread. As you will see if you carry out my mod, the other one simply won't work and will lead to catastrophic cam chain failure. He was sort of on the right track with his thoughts but failed to factor in a couple of very important points. Also as far as machining or " scraping " 5-7mms off the bottom of the housing, IMO it would not be a good idea. Firstly the bottom of the housing would become too weak and at the very least flex and leak oil. Secondly it would introduce the cylindrical section at the base of the housing too far into the engine and there is a couple of components just inside that it may foul against. Also you would be still relying on the original abortion of a spring setup to supply tension. My mod gives you the full range of original intended travel plus a little more. This is due to the fact that the plunger arrangement is now a perfect fit in the bore whereas the original loose fitting components allowed the operating end of the tensioner to flop up and down slightly. I disagree with the previous comment about adjusting manual tensioners until there is a certain amount of deflection in the chain. Simply ensure the engine is up to full operating temp and loosen the adjuster until you notice an audible cam chain noise and readjust tensioner until noise is gone plus about 1/8 to 1/4 of a turn more. Any tighter and you are simply wasting power and potentially increasing the wear rate of all the cam chain assembly components. Anyway I will post more info later. HAVE A BLAST! Paul.:thumb:
 

·
A Rainbird Warrior
Joined
·
5,154 Posts
G'day again, I have just completed the mod to the factory CCT to convert it to manual adjustment and it works absolutely fine. Later when my daughter arrives home I will post pictures of the mod as I have not got any idea of how you do it. Anybody who wants to do this mod will need to have a small sleeve machined up out of brass or mild steel. It needs to be 23mms long, 18.12mms outside diameter and have an 8mm hole bored all the way through it. I also machined 2 small grooves on the outside of this sleeve to take 2 o-rings. The original acme threaded device in the adjuster also has a couple of small mods done to it so as it effectively becomes the locking bolt for the mod. I will explain these mods once I post the pictures. 2 of the original parts are no longer used. They are the thin walled metal sleeve and the tensioning spring. In response to a couple of previous posts, firstly do not attempt the mod in the link provided earlier in this thread. As you will see if you carry out my mod, the other one simply won't work and will lead to catastrophic cam chain failure. He was sort of on the right track with his thoughts but failed to factor in a couple of very important points. Also as far as machining or " scraping " 5-7mms off the bottom of the housing, IMO it would not be a good idea. Firstly the bottom of the housing would become too weak and at the very least flex and leak oil. Secondly it would introduce the cylindrical section at the base of the housing too far into the engine and there is a couple of components just inside that it may foul against. Also you would be still relying on the original abortion of a spring setup to supply tension. My mod gives you the full range of original intended travel plus a little more. This is due to the fact that the plunger arrangement is now a perfect fit in the bore whereas the original loose fitting components allowed the operating end of the tensioner to flop up and down slightly. I disagree with the previous comment about adjusting manual tensioners until there is a certain amount of deflection in the chain. Simply ensure the engine is up to full operating temp and loosen the adjuster until you notice an audible cam chain noise and readjust tensioner until noise is gone plus about 1/8 to 1/4 of a turn more. Any tighter and you are simply wasting power and potentially increasing the wear rate of all the cam chain assembly components. Anyway I will post more info later. HAVE A BLAST! Paul.:thumb:


I like this Idea :thumb:


I also found this on the webb. would it be a similar unit for those who couldn't get it made?
 

·
Registered
Joined
·
543 Posts
Discussion Starter #9
I like this Idea :thumb:


I also found this on the webb. would it be a similar unit for those who couldn't get it made?
Yeah mate. It is basically what I have done, I just used most of the original bits and I have the bolt locking against a bush and some flat washers. Each time you choose to add some more tension, simply remove one of the washers.I will get the pics on soon! HAVE A BLAST! Paul.:)
 

·
Super Moderator
Joined
·
12,714 Posts
I have a manual adjuster fitted to my modified bike, the uprated spring item (although almost new) wasn't happy on the dyno when it was showing 190+ rwhp. There was a nasty knocking noise coming from under the cam covers!

IMHO there are pros and cons for manual adjusters.

Used properly they take some of the guesswork out of ensuring an engine is running correctly. But it means you have to keep on top of maintenance, something that so many do not / cannot do.

Manual adjusters are sometimes fitted to cover up over stretched cam chains before a bike is sold.

Swings and roundabouts I suppose.
 

·
Registered
Joined
·
173 Posts
Hi Justme

I thought that I posted that the modification to the CCT that I proposed was not a good idea for the reasons you mentioned. I replaced mine with an APE unit from Serco here in Brisbane.

I have had no problems with it at all. It was cheaper to go this way than to start serious mods on the Honda unit and besides the APE unit was anodised blue and thats got to be good.

I agree about the adjustment, the APE instructions called for removal of the cam cover and setting by deflection of the chain. I set it by feel on the adjuster screw to get it close then by ear. Doing it this way the adjustment was quiet at idle but noisy at 4k, a bit more on the screw fixed that.

JohnS
 

·
Registered
Joined
·
543 Posts
Discussion Starter #12
G'day again. Having problems uploading the pics. Says that the dimensions are too large. What do I do now? Reasonably handy with mechanical stuff, ****ing useless with computers !Thanks Paul.
 

·
Registered
Joined
·
543 Posts
Discussion Starter #13
Hi Justme

I thought that I posted that the modification to the CCT that I proposed was not a good idea for the reasons you mentioned. I replaced mine with an APE unit from Serco here in Brisbane.

I have had no problems with it at all. It was cheaper to go this way than to start serious mods on the Honda unit and besides the APE unit was anodised blue and thats got to be good.

I agree about the adjustment, the APE instructions called for removal of the cam cover and setting by deflection of the chain. I set it by feel on the adjuster screw to get it close then by ear. Doing it this way the adjustment was quiet at idle but noisy at 4k, a bit more on the screw fixed that.

JohnS
yeah mate, it was actually the mod by the chap from Sweeden that I was referring to as a failure waiting to happen.Trust me when I say there is nothing too seriously complex about this mod. Remember I am the dumb bugger that can't even upload the pics!:smilebig:
HAVE A BLAST! Paul.
 

·
Registered
Joined
·
1,832 Posts
Well the fix i posted is very common used here as the availability of CCT's is not that good....(15 days to 1 month to deliver - local dealer policy of not having stock for spares above a certain price)....since now i haven't heard any issues...but i'll be watching very closely and report...
 

·
Registered
Joined
·
116 Posts
Hi and thanx for your incredible work, Justme. But we're still waiting for the pictures to get everything right. :smilebig:
 

·
Registered
Joined
·
543 Posts
Discussion Starter #16
Hi and thanx for your incredible work, Justme. But we're still waiting for the pictures to get everything right. :smilebig:
Yeah G'day mate! I have not forgotten.I am working 12 hour days and am waiting to cross paths with my daughter so as she can give me a hand to upload the pics. jclaude has given us instructions on how to upload them. In the mean time here is the written instructions on how to do the mod. It is all very basic lathe work.

A/ Remove the CCT.
B/ Dismantle the CCT. Be very careful when taking off the external circlip so as you don't stretch it at all.
C/ You will no longer require the thin walled metal sleeve, the tensioning spring or the blanking bolt and sealing washer on the end of the unit.
D/ Clamp the acme threaded male portion of the adjuster in a 3 jaw chuck holding it by the slotted head. That slot was originally where the tension spring engaged. Later in the mod that portion of the unit will be cut off, but not until the mod is almost finished.
E/ Ensure the unit is running true and machine the boss of the unit down to 7.95mms in diameter. The same OD as that of the threaded area. This is machined down for the full length of the non threaded area up to and including the last relief where the thin walled sleeve use to locate. You will then be left with what looks like a round headed bolt with a strange looking thread.
D/ Now machine up a sleeve to the specs previously posted and machine 1 or 2 grooves in the outside for a thin o-ring or 2.
E/ Now hold the bolt securely in a vice by the slotted head. Don't worry if you squash the 2 halves together because that section is going to be machined off anyway.
F/ Clean all the parts well and apply a liberal coating of permanent loctite.
G/ Now slide the newly machined sleeve over the bolt and screw on the female portion of the original tensioning components. Do this up with a good fitting open ended spanner located on the flats on either side of this part.
H/ Clean off any excess loctite.
I/ You will now have a 1 part plunger unit that slides perfectly into the original CCT housing.
J/ Now hold the plunger unit in the 3 jaw chuck again. Holding it by the new sleeved area and face off the original slotted head. I then counter bored a very slight recess in there for the adjusting bolt to locate in . Would work just as well without it.
K/ Now find a 6mm metric bolt long enough to be used as an adjuster bolt and a locking nut. If you wont to be really fussy ensure the bolt is just long enough to not quite give you full travel on the adjuster so as it would be impossible to push the unit apart by over adjusting it. I did not worry about it because the cam chain and guides would be more than likely completely stuffed before you ran out of adjustment.
L/ Now coat the plunger with engine oil and reassemble the CCT.
M/ Now sit the CCT back in the engine without bolting it in and adjust the unit so as it is pushing the housing about 2-3 mm out of the engine. Now install the 2 mounting bolts and nip them up securely.
N/ Now start the engine and allow it to warm up. Loosen the adjusting bolt slowly until the cam chain starts to become noisy. Slowly screw it back in until noise is gone and give it about another 1/8 to 1/4 more of a turn clockwise and nip up the lock nut. There is no need to have a sealing washer under the lock nut because the o-rings on the outside of the plunger prevent engine oil from reaching that portion of the unit.
JOB DONE.
Not only is it an easy and cheap mod but it also has another advantage over the after market units. Honda went to some trouble to ensure it had a half rounded tip on the unit pushing on the tensioning blade so as no sharp edges were pushing on the blade. This feature is retained. It really is an easy machining job that can be done on any metal lathe regardless of size or condition. From start to finish it took me about an hour.

I will get the pictures uploaded. HAVE A BLAST! Paul.
 

·
Registered
Joined
·
4,853 Posts
To me there are 2 options

1.Either you stay automatic C.C.T let it do its own job and have him checked/replaced every 30.000 kms

2.Go manual and be more anxious and nervous having to check it every 5-7.000 kms to compensate for wear/free play etc.

I had my doubts when I installed my APE manual CCT....but it has been 2 years- and now....I would never go back to a crappy old auto CCT, ever.

Haven't had to touch it yet.



Lois



Lois
 

·
Registered
Joined
·
116 Posts
Thank you Justme, I'm going to try your method on my CCT. But before trying your method I already tried something different to another dead CCT from another Honda. The "bag of marbles" sound diseppeared after the process. Now let me tell you what I done.

First I remove the pin to remove the metal head (Maybe there is an english name for it, but I called that part as metal head) part from the body. Then measure it and with a lathe machine prepared another with the exact same size but only a little longer (6-7mm longer). Drilled the same hole in the smaller diameter part of the metal head for the pin. Installed the metal head to the body with the pin and insert the CCT to its place, then no more irritating sound. I'll inform you later.
 

·
Registered
Joined
·
543 Posts
Discussion Starter #20
Thank you Justme, I'm going to try your method on my CCT. But before trying your method I already tried something different to another dead CCT from another Honda. The "bag of marbles" sound diseppeared after the process. Now let me tell you what I done.

First I remove the pin to remove the metal head (Maybe there is an english name for it, but I called that part as metal head) part from the body. Then measure it and with a lathe machine prepared another with the exact same size but only a little longer (6-7mm longer). Drilled the same hole in the smaller diameter part of the metal head for the pin. Installed the metal head to the body with the pin and insert the CCT to its place, then no more irritating sound. I'll inform you later.
Yeah in theory that would work fine as well. Where did you get the specs for how many turns of preload are required on the spring when reassembled? How come the photos of the tips are identical except for the lengths, right down to any blemishes? Is that what they refer to as photoshopped?
HAVE A BLAST! Paul.
 
1 - 20 of 36 Posts
Top