A quick and dirty CCT stopper mod?

[KermitLeFrog]

Forgive me if I'm being thick but surely, if the front cylinder is at TDC on the compression stroke the CCT can be removed without affecting the tooth index. The chain will stay on the sprockets and not slip any teeth. I'm not sure that would be the case on the rear cylinder as it's more upright and the chain may miss the lower sprocket.

Anyway, if the chain stays on the correct teeth what's stopping you just removing the CCT and adding a stopper mod and putting it back?

Polite comments appreciated....

TIA
Ian

[MacV2]

At a guess its to do with the spring tension on the cams. You have to have it at the right spot on each cylinder when removing the CCT to prevent things going 'twang'...


I'm sure someone will be along shortly to give a better more technical answer than that...

[tony.mon]

The cams only travel at half crankshaft speed.
So the TDC mark occurs twice and the cams could either be in exactly the right position or exactly the wrong one.
You might be lucky, you might not.
if it's the wrong one the cams will be pushing down on the springs; take the tension off the cct and they will jump teeth.

Now, you will hear the clicks very clearly, so at that point you could then take the cam cover off and retime it.
50/50 chance.
But why mess around trying to take a shortcut when the cam cover comes off with four bolts? Takes seconds.
So no, not a realistic method.

[Cadbury64]

I see where kermit is coming from here, getting to the front cam cover is a huge PITA compared to the rear head. I'd think gravity would tend to hold the front chain in place when the tensioner pressure is removed as the tensioner blade is weighing down on the chain so unlikely for any slippage to occur.

There's surely a way to work out the front cylinder timing based on the easily accessed rear cylinder cam timing? The manual says when the rear timing mark and camshaft marks are properly aligned for TDC on that cylinder, then the front will be aligned with 450 degrees (1 1/4 turns) anticlockwise rotation.

[tony.mon]

I see where kermit is coming from here, getting to the front cam cover is a huge PITA compared to the rear head. I'd think gravity would tend to hold the front chain in place when the tensioner pressure is removed as the tensioner blade is weighing down on the chain so unlikely for any slippage to occur.

There's surely a way to work out the front cylinder timing based on the easily accessed rear cylinder cam timing? The manual says when the rear timing mark and camshaft marks are properly aligned for TDC on that cylinder, then the front will be aligned with 450 degrees (1 1/4 turns) anticlockwise rotation.

Yes, that WILL work, as long as the timing wasn't previously 180 degrees out, that is.

TBH that's about the method I use when setting the cct tension by feel and finger tension- feel what the rear one feels like in terms of how tight it is to the hand, and then set then front one the same.

I've probably done this more than most, though, and practice makes perfect, so they say.

If the chain slips over cam sprocket teeth as soon as you release the cct tension you can hear it quite easily- if you hear that it's time to man up and remove the front cover.
I don't find it too much work, really, if you undo the oil cooler mount bolts and remove it the cooler can rest against the rear of the front mudguard, no need to drain oil or coolant.
Put a rag on the mudguard or it's easy to scratch it.

I generally don't bother draining the coolant and removing the LH rad, but it's a lot easier to see the marks if you do. No need at all to disturb the RH one, the marks are on the LH side.

[rollingthunderx2]

What about forgetting all about timing, and simply cable tieing the cam chain to the cam sprocket so it can;t jump teeth, and doing the cct change then?

[Cadbury64]

That is the correct way to do the job; Ian was looking to save the grief of accessing the front cam cover, and just swapping the CCT over. Having gone through the full exercise myself, I can understand why he was looking to do so.

[rollingthunderx2]

But if you were going down the "vtr manual" way. would ziptieing on tdc on the cylinder being cct'd. or tensioner swapping make it simpler? The cam chain wuldn't jump because the cams would'nt have any valve spring tension on them?

[tony.mon]

In order to cable tie the chain to the sprocket, you have to take off the front cam cover, surely?

The original poster was trying to avoid that, I thought.

If your suggestion is followed then you could do that with the cams in any position, just pop the tops, cable tie and replace the cct.
However you can't set the tension on a manual one unless the engine is at the correct TDC for that cylinder, so it still needs to be set at the right place.

Now, if you have the inspection caps off in order to set and check that the engine is at TDC, and both cam covers are off in order to cable tie the chain on, why wouldn't you merely ensure that the cylinder was at the correct TDC instead of he one where the cams are pushing on the springs?

[thunderbolt]

But if you were going down the "vtr manual" way. would ziptieing on tdc on the cylinder being cct'd. or tensioner swapping make it simpler? The cam chain wuldn't jump because the cams would'nt have any valve spring tension on them?

To start with you would need to remove the valve cover to attach the zip tie which is the very thing OP was trying to avoid. Just bite the bullet and remove a few bits and get the front valve cover off. All you need to remove is the fairing, LH radiator and oil cooler. Tie a few bits out of the way and it's all good to go. About 4hrs work if that.

[thunderbolt]

Tony you beat me to it. Posted while I was typing.