CCT (Cam Chain Tensioner) Fail Safe Mod. (aka Stopper Mod)

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danno123
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Re: CCT (Cam Chain Tensioner) Fail Safe Mod. (aka Stopper Mod)

Post by danno123 »

I recently did the stopper mod on my motorcycle using advice found on this site. Here are a couple of observations:

- removing and replacing the hoses that attach to the gas tank is much easier with a set of "hose grip pliers." (I'm embarrassed to say how long it took me to remove and replace the tank without them).
- it was difficult for me to accurately measure the length of the stopper. I got the rear CCT length correct but was off by 1mm on the front, as demonstrated by the fact that, when I went to relieve tension on the spring, none released as it was already hitting the stopper. Then I was stuck filing down a little at a time. If I had to do it again, before I started the job I'd cut an 8mm bolt into various lengths off from 8mm to 12mm so I wouldn't have to file down one that was too long.
- make sure to turn the petcock back on after you're done. (oops).


I've also been giving some thought about Honda's original CCT. The CCT used on the VTR1000F is the same one used on the CBR series of inline 4-cylinder engines. But an inline 4 has a power pulse every 180 degrees of cam rotation. I believe the VTR has power pulses that are 450 and 170 degrees apart. In other words, the torque applied to rotate the VTR chain is done in a much more uneven manner and I can see where there is more opportunity for larger variations in slack/tension in the VTR cam chain than in the CBR for which this CCT was originally designed. Given this, I can see the attraction of a manual CCT. On the other hand, I've read a couple of instances of manual CCTs retracting because they were not locked down correctly and I think I'd be constantly worried about a manual CCT. All in all, I think the "stopper mod" is the best solution.
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sirch345
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Re: CCT (Cam Chain Tensioner) Fail Safe Mod. (aka Stopper Mod)

Post by sirch345 »

Good to hear your thoughts on the Stopper Mod Dan.
Glad you got there in the end, at least you're safe now if a CCT should fail :thumbup:

Chris.
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xeris
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Re: CCT (Cam Chain Tensioner) Fail Safe Mod. (aka Stopper Mod)

Post by xeris »

Fresh auto CCT's have been in a box for almost a year now, waiting for stopper mod and install . Remove the manuals and installed the autos with the stopper mod yesterday. All went well.
I went through and read all the threads on CCT install just to refresh my memory. I did not see anywhere in any of the how to threads a mention of the difference in the amount of chain slack between autos and the recommended amount for manuals. From memory, the manuals are recommended to have ~5mm or so of movement. The autos are tight, with no slack at all. No, I did not make the stopper piece too long. I was very careful to verify this before final bolt up.
Question, is this how the autos are supposed to be, or is something else going on? Seems to me that the amount of slack generally given for the manuals is more than a bit too much.
“I am quite sure now that often, very often, in matters concerning religion and politics a man’s reasoning powers are not above the monkey’s.”
~ Mark Twain
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sirch345
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Re: CCT (Cam Chain Tensioner) Fail Safe Mod. (aka Stopper Mod)

Post by sirch345 »

xeris wrote: Tue Jun 06, 2023 3:42 pm Fresh auto CCT's have been in a box for almost a year now, waiting for stopper mod and install . Remove the manuals and installed the autos with the stopper mod yesterday. All went well.
I went through and read all the threads on CCT install just to refresh my memory. I did not see anywhere in any of the how to threads a mention of the difference in the amount of chain slack between autos and the recommended amount for manuals. From memory, the manuals are recommended to have ~5mm or so of movement. The autos are tight, with no slack at all. No, I did not make the stopper piece too long. I was very careful to verify this before final bolt up.
Question, is this how the autos are supposed to be, or is something else going on? Seems to me that the amount of slack generally given for the manuals is more than a bit too much.
Good on you for refreshing your memory by taking the time to read up on fitting the new Auto CCT’s 👍👍

You are right in saying there is definitely less slack in the cam chain when Auto CCT’s are fitted compared to Manual CCT’s. It’s a fair time ago since I have checked this, but from memory I thought there were a few millimetres of slack in the cam chain with Auto CCT’s fitted.
It may be you needed to run your engine a few miles to settle down the tension set by the new Auto CCT’s before carrying out the Stopper Mod, unless you did that of course.

Not meaning to sound as if I’m doubting your work, but for piece of mind you can double check that your Stopper spacers are the right length by inserting a flat blade screwdriver in the end of your new Auto CCT’s, then turning the worm/screw clockwise you should get 1/2 of one full turn on the front cylinder, and 1/4 of one full turn on the rear cylinder before the CCT plunger hits the Stopper spacer meaning you won’t be able to turn the screwdriver any further. It won’t matter if you can turn the screwdriver a bit further than that before it stops turning, but you do need that amount of slack as stated above. Do that with the engine running as the tension will then tighten back up after removing the screwdriver. You will however have some oil coming out of the rear ACCT, so place a rag under the end to catch the oil before removing the end bolt for screwdriver access.

One of the reasons the MCCT’s need more slack in the cam chain adjustment is, you’re trying to get a happy medium throughout the rev range to compensate for the ACCT’s self adjusting.

Whether or not there needs to be less is a good question, IIRC Ape MCCT’s fitting instructions suggest the slack to be be in the range of 6mm to 9mm, although here on the Forum we think 7mm is maximum,

Chris.
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xeris
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Location: Bisbee, AZ

Re: CCT (Cam Chain Tensioner) Fail Safe Mod. (aka Stopper Mod)

Post by xeris »

sirch345 wrote: Tue Jun 06, 2023 6:37 pm
xeris wrote: Tue Jun 06, 2023 3:42 pm Fresh auto CCT's have been in a box for almost a year now, waiting for stopper mod and install . Remove the manuals and installed the autos with the stopper mod yesterday. All went well.
I went through and read all the threads on CCT install just to refresh my memory. I did not see anywhere in any of the how to threads a mention of the difference in the amount of chain slack between autos and the recommended amount for manuals. From memory, the manuals are recommended to have ~5mm or so of movement. The autos are tight, with no slack at all. No, I did not make the stopper piece too long. I was very careful to verify this before final bolt up.
Question, is this how the autos are supposed to be, or is something else going on? Seems to me that the amount of slack generally given for the manuals is more than a bit too much.
Good on you for refreshing your memory by taking the time to read up on fitting the new Auto CCT’s 👍👍

You are right in saying there is definitely less slack in the cam chain when Auto CCT’s are fitted compared to Manual CCT’s. It’s a fair time ago since I have checked this, but from memory I thought there were a few millimetres of slack in the cam chain with Auto CCT’s fitted.
It may be you needed to run your engine a few miles to settle down the tension set by the new Auto CCT’s before carrying out the Stopper Mod, unless you did that of course.

Not meaning to sound as if I’m doubting your work, but for piece of mind you can double check that your Stopper spacers are the right length by inserting a flat blade screwdriver in the end of your new Auto CCT’s, then turning the worm/screw clockwise you should get 1/2 of one full turn on the front cylinder, and 1/4 of one full turn on the rear cylinder before the CCT plunger hits the Stopper spacer meaning you won’t be able to turn the screwdriver any further. It won’t matter if you can turn the screwdriver a bit further than that before it stops turning, but you do need that amount of slack as stated above. Do that with the engine running as the tension will then tighten back up after removing the screwdriver. You will however have some oil coming out of the rear ACCT, so place a rag under the end to catch the oil before removing the end bolt for screwdriver access.

One of the reasons the MCCT’s need more slack in the cam chain adjustment is, you’re trying to get a happy medium throughout the rev range to compensate for the ACCT’s self adjusting.

Whether or not there needs to be less is a good question, IIRC Ape MCCT’s fitting instructions suggest the slack to be be in the range of 6mm to 9mm, although here on the Forum we think 7mm is maximum,

Chris.
I was thinking of running the autos a bit before adding the stopper, but having only two gaskets and wanting to be done with the install, I just went for it.
I did a dry fit with the stopper pieces and checked the full retraction. I had to re-cut a little longer piece for the rear to get the right amount when fully retracted.
I found it interesting that after removing the key to set tension on the chain, then rotating the engine to TDC compression on the same cylinder again, their was about an 1/8 more turn on the key to reach the stopper limit on both the front and rear.
“I am quite sure now that often, very often, in matters concerning religion and politics a man’s reasoning powers are not above the monkey’s.”
~ Mark Twain
tony.mon
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Re: CCT (Cam Chain Tensioner) Fail Safe Mod. (aka Stopper Mod)

Post by tony.mon »

You definitely need to leave a little slack in the stopper at all points of crankshaft rotation, about 1mm is enough.
If too tight it will pull the cam down onto its journal and you can damage the head as well as the cam.
Neither are repairable so you would have to replace them.
It's not falling off, it's an upgrade opportunity.
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sirch345
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Re: CCT (Cam Chain Tensioner) Fail Safe Mod. (aka Stopper Mod)

Post by sirch345 »

xeris wrote: Wed Jun 07, 2023 2:22 pm
sirch345 wrote: Tue Jun 06, 2023 6:37 pm
xeris wrote: Tue Jun 06, 2023 3:42 pm Fresh auto CCT's have been in a box for almost a year now, waiting for stopper mod and install . Remove the manuals and installed the autos with the stopper mod yesterday. All went well.
I went through and read all the threads on CCT install just to refresh my memory. I did not see anywhere in any of the how to threads a mention of the difference in the amount of chain slack between autos and the recommended amount for manuals. From memory, the manuals are recommended to have ~5mm or so of movement. The autos are tight, with no slack at all. No, I did not make the stopper piece too long. I was very careful to verify this before final bolt up.
Question, is this how the autos are supposed to be, or is something else going on? Seems to me that the amount of slack generally given for the manuals is more than a bit too much.
Good on you for refreshing your memory by taking the time to read up on fitting the new Auto CCT’s 👍👍

You are right in saying there is definitely less slack in the cam chain when Auto CCT’s are fitted compared to Manual CCT’s. It’s a fair time ago since I have checked this, but from memory I thought there were a few millimetres of slack in the cam chain with Auto CCT’s fitted.
It may be you needed to run your engine a few miles to settle down the tension set by the new Auto CCT’s before carrying out the Stopper Mod, unless you did that of course.

Not meaning to sound as if I’m doubting your work, but for piece of mind you can double check that your Stopper spacers are the right length by inserting a flat blade screwdriver in the end of your new Auto CCT’s, then turning the worm/screw clockwise you should get 1/2 of one full turn on the front cylinder, and 1/4 of one full turn on the rear cylinder before the CCT plunger hits the Stopper spacer meaning you won’t be able to turn the screwdriver any further. It won’t matter if you can turn the screwdriver a bit further than that before it stops turning, but you do need that amount of slack as stated above. Do that with the engine running as the tension will then tighten back up after removing the screwdriver. You will however have some oil coming out of the rear ACCT, so place a rag under the end to catch the oil before removing the end bolt for screwdriver access.

One of the reasons the MCCT’s need more slack in the cam chain adjustment is, you’re trying to get a happy medium throughout the rev range to compensate for the ACCT’s self adjusting.

Whether or not there needs to be less is a good question, IIRC Ape MCCT’s fitting instructions suggest the slack to be be in the range of 6mm to 9mm, although here on the Forum we think 7mm is maximum,

Chris.
I was thinking of running the autos a bit before adding the stopper, but having only two gaskets and wanting to be done with the install, I just went for it.
I did a dry fit with the stopper pieces and checked the full retraction. I had to re-cut a little longer piece for the rear to get the right amount when fully retracted.
I found it interesting that after removing the key to set tension on the chain, then rotating the engine to TDC compression on the same cylinder again, their was about an 1/8 more turn on the key to reach the stopper limit on both the front and rear.
That all sounds good to me👍

The 1/8th more turn on the key is likely due to the cam chain being in a different position even though you had the piston at TDC. Even so 1/8th of a turn more is not a huge amount, also better to be slightly more than slightly less,

Chris.
gorana
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Re: CCT (Cam Chain Tensioner) Fail Safe Mod. (aka Stopper Mod)

Post by gorana »

sirch345 wrote: Tue Jun 06, 2023 6:37 pm
xeris wrote: Tue Jun 06, 2023 3:42 pm Fresh auto CCT's have been in a box for almost a year now, waiting for stopper mod and install . Remove the manuals and installed the autos with the stopper mod yesterday. All went well.
I went through and read all the threads on CCT install just to refresh my memory. I did not see anywhere in any of the how to threads a mention of the difference in the amount of chain slack between autos and the recommended amount for manuals. From memory, the manuals are recommended to have ~5mm or so of movement. The autos are tight, with no slack at all. No, I did not make the stopper piece too long. I was very careful to verify this before final bolt up.
Question, is this how the autos are supposed to be, or is something else going on? Seems to me that the amount of slack generally given for the manuals is more than a bit too much.
Good on you for refreshing your memory by taking the time to read up on fitting the new Auto CCT’s 👍👍

You are right in saying there is definitely less slack in the cam chain when Auto CCT’s are fitted compared to Manual CCT’s. It’s a fair time ago since I have checked this, but from memory I thought there were a few millimetres of slack in the cam chain with Auto CCT’s fitted.
It may be you needed to run your engine a few miles to settle down the tension set by the new Auto CCT’s before carrying out the Stopper Mod, unless you did that of course.

Not meaning to sound as if I’m doubting your work, but for piece of mind you can double check that your Stopper spacers are the right length by inserting a flat blade screwdriver in the end of your new Auto CCT’s, then turning the worm/screw clockwise you should get 1/2 of one full turn on the front cylinder, and 1/4 of one full turn on the rear cylinder before the CCT plunger hits the Stopper spacer meaning you won’t be able to turn the screwdriver any further. It won’t matter if you can turn the screwdriver a bit further than that before it stops turning, but you do need that amount of slack as stated above. Do that with the engine running as the tension will then tighten back up after removing the screwdriver. You will however have some oil coming out of the rear ACCT, so place a rag under the end to catch the oil before removing the end bolt for screwdriver access.

One of the reasons the MCCT’s need more slack in the cam chain adjustment is, you’re trying to get a happy medium throughout the rev range to compensate for the ACCT’s self adjusting.

Whether or not there needs to be less is a good question, IIRC Ape MCCT’s fitting instructions suggest the slack to be be in the range of 6mm to 9mm, although here on the Forum we think 7mm is maximum,

Chris.
Hi Chris,
Thanks for the guide for the Stopper mid, and all other info about it!
I'm about to do it after reading all I have found about it.
Just to make sure, after double checking with the engine running that the Stopper spacers are the right length, shouldn't they be reset, i.e. turned anti-clockwise the same amount?

Cheers,
Goran
tony.mon
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Joined: Wed Jul 25, 2007 10:46 pm
Location: Norf Kent

Re: CCT (Cam Chain Tensioner) Fail Safe Mod. (aka Stopper Mod)

Post by tony.mon »

Hi Chris,
Thanks for the guide for the Stopper mid, and all other info about it!
I'm about to do it after reading all I have found about it.
Just to make sure, after double checking with the engine running that the Stopper spacers are the right length, shouldn't they be reset, i.e. turned anti-clockwise the same amount?

Cheers,
Goran
_--------------------
No need, Goran, as soon as you release the screwdriver they will reset themselves under spring tension.
It's not falling off, it's an upgrade opportunity.
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sirch345
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Re: CCT (Cam Chain Tensioner) Fail Safe Mod. (aka Stopper Mod)

Post by sirch345 »

Goran, as Tony says, the standard CCT will self adjust with the engine running once you remove the screwdriver.

Chris.
gorana
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Joined: Wed Aug 28, 2019 3:41 pm

Re: CCT (Cam Chain Tensioner) Fail Safe Mod. (aka Stopper Mod)

Post by gorana »

tony.mon wrote: Tue Aug 15, 2023 3:35 pm Hi Chris,
Thanks for the guide for the Stopper mid, and all other info about it!
I'm about to do it after reading all I have found about it.
Just to make sure, after double checking with the engine running that the Stopper spacers are the right length, shouldn't they be reset, i.e. turned anti-clockwise the same amount?

Cheers,
Goran
_--------------------
No need, Goran, as soon as you release the screwdriver they will reset themselves under spring tension.
Hi Tony,
Thanks!
I will try to do it today.
Cheers,
Goran
gorana
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Joined: Wed Aug 28, 2019 3:41 pm

Re: CCT (Cam Chain Tensioner) Fail Safe Mod. (aka Stopper Mod)

Post by gorana »

sirch345 wrote: Tue Aug 15, 2023 5:12 pm Goran, as Tony says, the standard CCT will self adjust with the engine running once you remove the screwdriver.

Chris.
Hi Chris,
Thanks!
Will try to do it later today.
Cheers,
Goran
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