So Iv been doing none stop research and have come to the conclusion that im going to perform the Stopper mod on my new Honda Auto cct's
Iv got a quick question with regards to the thread by Chris aka Sirch345 http://www.vtr1000.org/phpBB3/viewtopic ... 31&t=19416
How do you work out distance 'A' on the diagram (Which is the length of the metal rod insert)
My idea is to carry out the mod on the new CCT's iv got, then to hand them all to the local Honda ind specialist. Hes quoted me £120 (which is worst case) to fit the new CCT's and to check the valve clearences at the same time.....
Regards Scott
Stopper mod question
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scott02464
- Posts: 796
- Joined: Wed Dec 28, 2011 2:04 pm
- Location: Tadcaster- Near York
Re: Stopper mod question
Measurement A has to be worked out on the bike as the stopper is made to measure for each specific CCT. Even your back and front will be a different size to each other.
With the engine at tdc for the rear cyl, you lock the CCT in its working position, and from there you establish what "A" is for that cyl. Then repeat for the front?
It's nt the CCT that you are compensating for, it is the slack in the chain and other tolerances in the engine, so you can't do it on spare CCTs without trial fitting them into the engine to work out the normal working length.
With the engine at tdc for the rear cyl, you lock the CCT in its working position, and from there you establish what "A" is for that cyl. Then repeat for the front?
It's nt the CCT that you are compensating for, it is the slack in the chain and other tolerances in the engine, so you can't do it on spare CCTs without trial fitting them into the engine to work out the normal working length.
AMcQ
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scott02464
- Posts: 796
- Joined: Wed Dec 28, 2011 2:04 pm
- Location: Tadcaster- Near York
Re: Stopper mod question
Im with you mate, thanks for that.
Ill have to supply the actual rod insert and ask the specialist to cut to the correct length
Thanks again mate
Ill have to supply the actual rod insert and ask the specialist to cut to the correct length
Thanks again mate
Re: Stopper mod question
i take it distance (a) is - set working poition (less 1/4 turn rear or 1/2 turn front), remove from engine and then do you work the distance from working position to the plunger being fully retracted?
Re: Stopper mod question
I've set this out in stages so that it can be printed off and used as a checklist.
The length needed is easy to work out:
Firstly set the engine to that cylinder's correct position- start with the rear because it's easy to take off the tank and rear cam cover to see whether the cams are in the right place.
Next, lock off the cct with a locking tool.(*)
Undo the cct mounting cap head screws, and remove it (the rear one will leak a few cc's of oil, so place a rag beneath to catch the drips and avoid you ruining the front room carpet, assuming you're doing it indoors due to the rain.
With the cct in your hand, measure the gap between the base of the rubber end blob, where the rod enters it, and the base of the casting. It'll be somewhere around or just under 20mm, usually. Write it down.
Now carefully drive out the little roll pin holding the end blob in place. I use a small pop rivet; as long as the rivet shaft is smaller diameter than the roll pin it works fine. Don't drop it- they're easy to lose! (but steel, so you can trawl through the dust and grit with a magnet to find it again). Remove the end rubber blob, with its steel cap.
Take an old 8mm bolt, and cut off about 13mm from the thread end. You don't need to use the thread, so it doesn't matter if it's threaded all the way or not.
Remove the locking tool.
Slide the stopper into the plunger rod, and using the rivet stem instead of the roll pin, reassemble the unit.
Retract the plunger as far as it will go, and measure the gap between the blob and the body of the cct again.
You need to shorten the stopper until the gap you get is 1.5mm less than the original measurement.
Do this by filing or grinding the stopper . Doesn't have to be neat, or perfectly flat, or beautiful, as no-one will ever see it again.
Lengths needed vary, but often 10-13 mm or so is about right.
Once you're happy that the roll pin holes will now line up, it is now possible to push the rivet stem through the holes, to temporarily re-attach the end blob.
Retract the cct as far as it will go.
Measure the gap again, and compare it to your previous measurement. It should be 1,5mm shorter than your original measurement when fully retracted as far as it will go.
Once you're happy with the length of the stopper, remove the rivet stem, then refit the roll pin.
Now retract the plunger as far as it will go, and measure the gap, just to check. It should be 1.5mm less than you measured when you first took it out.
If that's correct, lock it off fully retracted and refit.
Now turn the engine one and a quarter turns anti clockwise, until the FT mark lines up in the inspection window, and do the same to the front one; you don't need to remove the cam cover this time as you know that the engine will be in the correct place.
You don't need a specialist engineering workshop to cut a bit off the end of a bolt; they'd laugh at you. All you need for this job is a hacksaw and a file, and one M8 bolt of 30mm or more thread length.
(*) If you don't have a locking tool, you can hold the plunger in place with a small flat blade screwdriver, just remember to crack the cap head screws holding the CCT in place first so that they can be easily undone with one hand on an allen key while you hold the screwdriver in place with the other.
You won't be able to let it go or put it down until you've measured the gap, so make sure that you have a measuring device (vernier calipers are best, but a ruler will do- no real accuracy needed) are easily to hand.
If the screwdriver slips, just retract it, re-insert and start again, until you have a good measurement to start with.
Once that's done, it doesn't matter if you let go, just wind it back in again each time.
I've used a small pop rivet in the above example, but any thin rod will do- a piece of welding rod, for example.
As long as it's thinner than the roll pin itself.
It seems a good idea to take it in small stages, and make absolutely sure that you get it right.
By the way, feel for good spring tension with a small flat blade screwdriver with both cct's- if one feels weak, or it's not smooth in operation, then the spring may already be on it's way out and you should consider your options before proceeding. You should be able to turn the screw against spring pressure until the rod is fully retracted, and upon releasing the screwdriver it will spring out again to it's fully extended position.
No point fitting a cct stopper to a cct that's going to have a failed spring soon anyway.
The length needed is easy to work out:
Firstly set the engine to that cylinder's correct position- start with the rear because it's easy to take off the tank and rear cam cover to see whether the cams are in the right place.
Next, lock off the cct with a locking tool.(*)
Undo the cct mounting cap head screws, and remove it (the rear one will leak a few cc's of oil, so place a rag beneath to catch the drips and avoid you ruining the front room carpet, assuming you're doing it indoors due to the rain.
With the cct in your hand, measure the gap between the base of the rubber end blob, where the rod enters it, and the base of the casting. It'll be somewhere around or just under 20mm, usually. Write it down.
Now carefully drive out the little roll pin holding the end blob in place. I use a small pop rivet; as long as the rivet shaft is smaller diameter than the roll pin it works fine. Don't drop it- they're easy to lose! (but steel, so you can trawl through the dust and grit with a magnet to find it again). Remove the end rubber blob, with its steel cap.
Take an old 8mm bolt, and cut off about 13mm from the thread end. You don't need to use the thread, so it doesn't matter if it's threaded all the way or not.
Remove the locking tool.
Slide the stopper into the plunger rod, and using the rivet stem instead of the roll pin, reassemble the unit.
Retract the plunger as far as it will go, and measure the gap between the blob and the body of the cct again.
You need to shorten the stopper until the gap you get is 1.5mm less than the original measurement.
Do this by filing or grinding the stopper . Doesn't have to be neat, or perfectly flat, or beautiful, as no-one will ever see it again.
Lengths needed vary, but often 10-13 mm or so is about right.
Once you're happy that the roll pin holes will now line up, it is now possible to push the rivet stem through the holes, to temporarily re-attach the end blob.
Retract the cct as far as it will go.
Measure the gap again, and compare it to your previous measurement. It should be 1,5mm shorter than your original measurement when fully retracted as far as it will go.
Once you're happy with the length of the stopper, remove the rivet stem, then refit the roll pin.
Now retract the plunger as far as it will go, and measure the gap, just to check. It should be 1.5mm less than you measured when you first took it out.
If that's correct, lock it off fully retracted and refit.
Now turn the engine one and a quarter turns anti clockwise, until the FT mark lines up in the inspection window, and do the same to the front one; you don't need to remove the cam cover this time as you know that the engine will be in the correct place.
You don't need a specialist engineering workshop to cut a bit off the end of a bolt; they'd laugh at you. All you need for this job is a hacksaw and a file, and one M8 bolt of 30mm or more thread length.
(*) If you don't have a locking tool, you can hold the plunger in place with a small flat blade screwdriver, just remember to crack the cap head screws holding the CCT in place first so that they can be easily undone with one hand on an allen key while you hold the screwdriver in place with the other.
You won't be able to let it go or put it down until you've measured the gap, so make sure that you have a measuring device (vernier calipers are best, but a ruler will do- no real accuracy needed) are easily to hand.
If the screwdriver slips, just retract it, re-insert and start again, until you have a good measurement to start with.
Once that's done, it doesn't matter if you let go, just wind it back in again each time.
I've used a small pop rivet in the above example, but any thin rod will do- a piece of welding rod, for example.
As long as it's thinner than the roll pin itself.
It seems a good idea to take it in small stages, and make absolutely sure that you get it right.
By the way, feel for good spring tension with a small flat blade screwdriver with both cct's- if one feels weak, or it's not smooth in operation, then the spring may already be on it's way out and you should consider your options before proceeding. You should be able to turn the screw against spring pressure until the rod is fully retracted, and upon releasing the screwdriver it will spring out again to it's fully extended position.
No point fitting a cct stopper to a cct that's going to have a failed spring soon anyway.
It's not falling off, it's an upgrade opportunity.
Re: Stopper mod question
Scott, I won't add to your question, as I see you've already done this mod.
Yes, distance (A) is the set working position (less 1/4 rear or 1/2 turn front). What you are doing is filling that void [which is distance (A)].
In the event of a CCT failing the screw/worm inside the CCT will use up that void (distance (A) as the plunger retracts. It's because the plunger can retract that the cam chain then becomes slack enough to jump the cam sprockets. Once that happens the valve timing is then out causing the valves to be smacked and bent by the piston.
Filling that void/space [distance (A)] stops the plunger retracting in the event of a CCT failure. This then means the cam chain cannot become slack enough to jump the cam sprockets.
NOTE
Make sure you follow the procedure for setting the valve timing in this link before removing either CCT:-
http://www.vtr1000.org/phpBB3/viewtopic.php?f=31&t=8326
Chris.
You're half right.vtrjames wrote:i take it distance (a) is - set working poition (less 1/4 turn rear or 1/2 turn front), remove from engine and then do you work the distance from working position to the plunger being fully retracted?
Yes, distance (A) is the set working position (less 1/4 rear or 1/2 turn front). What you are doing is filling that void [which is distance (A)].
In the event of a CCT failing the screw/worm inside the CCT will use up that void (distance (A) as the plunger retracts. It's because the plunger can retract that the cam chain then becomes slack enough to jump the cam sprockets. Once that happens the valve timing is then out causing the valves to be smacked and bent by the piston.
Filling that void/space [distance (A)] stops the plunger retracting in the event of a CCT failure. This then means the cam chain cannot become slack enough to jump the cam sprockets.
NOTE
Make sure you follow the procedure for setting the valve timing in this link before removing either CCT:-
http://www.vtr1000.org/phpBB3/viewtopic.php?f=31&t=8326
Chris.