Noise from rear CCT

[VenerableArc]

Finally found some time today to change my CCTs to manual ones courtesy of bazza. However upon start up the rear CCT was making alot more noise than I would have expected. The front CCT make no noise whatsoever. To make a comparison the rear sounded like a ducati dry clutch. Tick tick tick tick etc. Have no fear as soon as I was aware of the noise the bike was shut off straight away.

Has this happened because I have slightly over tightened the rear CCT? Or am I being over protective. In hindsight I should have taken a video and posted it on here. I will do this tomorrow if it helps.

On a side note....whilst checking the TDC marks on the front cams, I noticed that the Front Intake mark was miles away from where it should have been. I had to jump the sprocket 3 teeth to get it lined up. What could this mean? Will I notice a difference on my next ride? I.e more power/top end etc?

Many thanks.

Ps here is a photo of my trusty helper

[VTRDark]

Lets start with the rear. It would not be making any tapping/rattling noise if over tight. You would get a high pitched screeching noise and/or the bike would be very slow or struggle to turn over. How did you set the tension on the chain? It's normal to get a slight noise with a cold engine and this should disappear as the engine warms up. But a lot of noise, no, and it should not sound like a Ducati. You may have not tightened it up enough.

Onto the front. Three teeth is a lot and borderline valves touching the piston. I'm wondering if there has been a failure in the past. Either that or some numpty has had a go at valve clearances and put the cam back in wrong. On that note you should check the valve clearances if it was out that much. I would also check the rears while your at it. Three teeth will make a considerable difference to how the bike runs. How did it run/sound like before?

(:-})

[VenerableArc]

Hi Carl thanks for the response.

I tensioned the chain as per the CCT manual you produced on here:- 5-7mm of up and down motion. On the final check - turn the engine over one cycle to check for free rotation, everything was fine and I had no trouble turning the engine over. Is it worth me running the bike until warm and seeing if it disappears?

The chap I bought the bike from didn't mention any previous failures and going through the past paperwork there is no evidence of such work being carried out, but that's not to say it didn't happen.

As for how the bike ran before. It seemed to run okay apart from cutting out occasionally at idle and struggling for power when in 4th/5th and the throttle was opened right up - 3/4 throttle seemed to work better and full throttle. As for top speed, I struggled to get close to what MCN said it's top speed was (144mph - on a private road of course ;) ) but then again we all know MCN talk utter bull.

Is there a guide on here on how to check for valve clearances?

Looks like me and Jess will be back out to the garage tomorrow night

Matt

[8541Hawk]

As for how the bike ran before. It seemed to run okay apart from cutting out occasionally at idle and struggling for power when in 4th/5th and the throttle was opened right up - 3/4 throttle seemed to work better and full throttle. As for top speed, I struggled to get close to what MCN said it's top speed was (144mph - on a private road of course ;) ) but then again we all know MCN talk utter bull.

Well I'm not sure about mag. tests but I can say that I have had my bike hit the rev limiter (back when I had a rev limiter) in 6th with stock gearing. which should be somewhere between 158-160 MPH.
So even a completely stock bike should be able to do better than 144 MPH.

If I remember correctly I was able to get around 9800 RPM with a completely stock bike which should be a bit over 150MPH

[VTRDark]

Your probably just hearing the noise of the slack chain while cold. Did you take the measurement from the outside edge. From your description (Ducati ) I have a feeling you may be a little slack and maybe need to tighten it up 1/4 - 1/2 turn. As long as it turns over freely then I would let the bike warm up fully and see if things quieten down.

What worries me is the vast difference between the front and rear cylinder. From what you describe they are at completes opposites, one too noisy, and one too quiet. This is anther reason for checking valve clearances. You may also be confusing the sound of the chain with valves or viva-verca. Struggling for power when in 4th/5th is not normal and bad cam alignment and/or valve clearances will contribute to a bad idle and cutting out. I'm still not convinced that there is no previous valve damage but we wont go there for now The thing to remember is that a chain can't just go and jump 3 teeth by itself. Now considering you where 3 teeth out, you should notice a considerable improvement with the cams aligned properly. It will also affect your fulling, so you will need to adjusts you idle speed and balance the carbs at some stage. But do check you valve clearances first.

There's no guides for Valve clearances as there is not much to explain. Page 3-7 Maintenance section in the Honda workshop manual will give you an idea. Basically with the cylinder at TDC on the compression stroke (same as CCT's). Basically slip a feeler gauge between the base of the cam and the valve bucket and find which feeler slides in and out smoothly with slight resistance, so you can just feel it biting. It's one of those things where practise makes perfect until you get the feel for things. Be careful with sliding and bending the feeler as this can put pressure on it and mislead you into a false reading. It's best to use feeler gauges that are angled from factory for awkward spaces but straight ones work fine if you careful. I tend to hold the feeler before the bend so it straight in at the point I want it. As long as you within spec you should be fine.

The Honda Manual only gives the one size.
Inlet 0.16mm
Exhaust 0.31mm

The Haynes manual gives you a range to be within
Inlet 0.13mm - 0.19mm
Exhaust 0.28 - 0.34mm

In an ideal world you would be at the largest as the gap closes as things wear. But as long as you anywhere in between then you will be fine. The Honda manual just gives you the average.

(:-})

[VenerableArc]

I will run the bike this evening and let it get up to temperature before checking my clearances, I will also give it 1/4 to 1/2 a turn then re-run and see if this solves the issue if the noise doesn't die down. I will also try and get a recording of the noise just in case I need to further help.

I have a set of gauges in my toolbox at work so can do the clearances tonight too - providing the Mrs doesn't rope me into DIY!!

The measurement was taken from the outside edge yes, however I aired on the side of caution so it was more 7mm than 5mm.

Thanks for your input, really appreciate it. Lets hope the valve clearances are okay and the noise is due to lack of tension

Matt

[VenerableArc]

As an update I have just checked the tension of the rear CCT and it was extremely slack. Not sure how it got in that state at the nut was bollocked up. Anyways that has been out right, however I haven't started the bike as I am still in the middle of checking the clearances. My rear ones are well within tolerances. My front inlet is >.10 and < .15. (My collection of feelers isnt great! I haven't done the exhaust as of yet as I am waiting to be picked up. Will measure the front exhaust later/tomorrow.

If the inlet is less than .13 what is my next move? I will pop out tomorrow to get a better set of gauges.

Matt

[VTRDark]

Which nut was bollocked up and in what way? Don't forget to apply sealant to the tensioner thread before winding it in and locking off.

Back to the Valve clearances. If the clearance is out of spec then you should re-shim to get it back within spec. But you getting into a whole new trip then. How do you feel about removing cams. The shims are under the valve buckets!

Ow sh1t....I'm starring at this screen and I'm strting to spin out. :beer had kicked in : Sorryy I can't write more right now. I'l get back to you later it's beddy byes time .ZZZZZZzzzzzz

(:-})

[VTRDark]

Sorry about that.

To re-shim...Decide what measurement you want it in spc by and you need to work out by how much it's out by , take the cam/s off, remove shim. To do this use a magnet on stick to lift the bucket off and the shim usually comes off with it. If not it will stick into the recess in top of the valve spring cap. Be cartful not loose it inside the cylinder head anywhere or drop it down inside the engine. Use the magnet where you can to get both the bucket and shim off.

Measure the shim, add your measurement from earlier, then replace with the appropriate size shim. So the size of shim plus measurement = new shim size. Now this is an issue, unless you have a shim kit to hand with various size shims then you will have to order the right shim. You will be waiting on deliveries then Replace shim with wither the appropriate size or as close to it. Slide the bucket back on, cams back on and all back together. then double check your measurements and makes sure it's within spec now.

Personally I would take my time, purchase a shim kit and get them all spot on....well, as close as I could to the largest within spec measurement. As they wear IIRC the gap clearance closes up. It's the more expensive and time consuming route, but then I would not have to fuss around measuring and then ordering the shims individually, and I will have shims for a rainy day if I need them. any excuse for a new tool to the collection or to buy something that is needed

Valve clearances are all done properly then and you don't have to worry about them until the next service limit. Out of curiosity, what's the milage on your bike?

(:-})

[VenerableArc]

Basically the locknut that keeps the long bolt in place (the one going through the CCT) was done up tight. So I must have made a booboo in my tensioning as the chain was too loose. Must have had my silly head on.

Anyways the shimming sounds easy enough and I have access to possibly the worlds largest supply of rayshims going (I do pump alignment as part of my job). That's if it is under tolerances. I need to get my hands on a 0.12, 0.13mm and 0.14mm feeler gauge to be sure though.

The bike has covered 24000 miles Carl and she is a T plate.

PS i owe you a for your help and guidance master jedi

Matt

[VTRDark]

I'm glad you stopped the engine when you did. It may have unwound itself this is one of the reason for sealant. Sealant in the thread hole and under and around the locknut when tightening up. The sealant in the the thread hole (once dry!) serves two purposes..one, it stop any oil creeping along the thread and leaking. And two, act as a brake to slow the thread from unwinding on itself. Gives it some resistance!

Make sure when locking off you hold the bolt on the opposite end at the same time.

I had to get a new set of feelers recently. My old Snap On ones where rusty and the scales where wearing of the face of some. I don't like having to replace tools I've had for donkeys years and it comes to the end of their life. I swear I have an attachment to my tools

I had a good beer last night.

(:-})

[VenerableArc]

Hi Carl, just an update. Both front cams are in tolerance. The inlet was 0.14 and the exhaust was 0.30. I will have to strip the bike down this time next year and keep and eye on the front inlet.

Started the bike up and the tick tick tick noise heard previously has gone.

Thanks again

[VTRDark]

Good news. Time to get out and ride it then.

(:-})

[VenerableArc]

The fairing is off at the moment as I'm giving her a complete respray however I've only started on the rear end so will be taxing her this weekend and refitting the half sprayed fairings this weekend. will repost when I've ridden her