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Discussion Starter · #1 ·
I was given carbon build up as the reason for my valve clearances needing checking by the local triumph workshop on my legend with only 10000ks on it.It has never been done and the manual states 20000ks or every 2 years.Can someone explain to me how you get valve recession in a motor thats barely run.Example:You set the clearances and do only 2000ks
in 2 years yet you would be due to check again.Why?
 

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I was given carbon build up as the reason for my valve clearances needing checking by the local triumph workshop on my legend with only 10000ks on it.It has never been done and the manual states 20000ks or every 2 years.Can someone explain to me how you get valve recession in a motor thats barely run.Example:You set the clearances and do only 2000ks
in 2 years yet you would be due to check again.Why?
I did them 1st on my Legend at ~ 10,000kms but 3 were only slightly out. I reshimmed because I was there anyway. They would have done another 10k for sure imo. I believe the idea is that the valve seats will bed in a little more in the early miles on the engine & then wear a little less. Hence the 1st check at 10k then 20k thereafter in my Legend manual. (Tho' I've seen Tbird schedules just say every 20k, skipping the 1st 10k check.) They're none too critical imo - the first Tbird I had was down to 1 thou" on 2 inlets & ran just fine before I reshimmed. No idea what the guy's on about with 'carbon buildup'. Where? What makes him think that & what have the valves clearances to do with it?
 

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Discussion Starter · #3 ·
He said carbon build up around the valve seats but sounds like rubbish to me.I am just going to wait to 20000ks.My 96 speed triple required 1 shim in 60000ks from new and I paid out a fortune having the bloody things checked 3 time in that period.
 

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He said carbon build up around the valve seats but sounds like rubbish to me.I am just going to wait to 20000ks.My 96 speed triple required 1 shim in 60000ks from new and I paid out a fortune having the bloody things checked 3 time in that period.
Carbon build-up could potentially open the valve clearance but I think the more likely scenario is that the valve seat wears slightly making the valve clearance tighter. Either way, I wouldn't sweat it too much. My Thunderbird has 43000 miles on it and only changed two shims on it in all that time.

Noel
 

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He said carbon build up around the valve seats but sounds like rubbish to me.I am just going to wait to 20000ks.My 96 speed triple required 1 shim in 60000ks from new and I paid out a fortune having the bloody things checked 3 time in that period.
Yes, that's [email protected], it is not carbon or any other kind of buildup.

You do need to do the valve check at 3,000 then every 6,000 after that. The reason is simply wear - the valves recede into the head as they and the seats wear - the change is more pronounced at first as things are bedding in. The danger of not doing this check is that things will close up so much that the valves don't close properly - the result is a burnt out valve / seat. Due to the fact that the tolerances actually close up with wear (rather than expand like on older non DOHC bikes), you will have no audible symptoms that its time to do the adjustment. Checking is quick and pretty easy, changing the shims is a little harder but straightforward with the right tools. If you are worried about doing it, you can go half way - do the check yourself and if you find it needs adjustment then puit it back together and take it to the dealer / a good bike mechanic to do the actual adjustment.
 

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Yes, that's [email protected], it is not carbon or any other kind of buildup.

You do need to do the valve check at 3,000 then every 6,000 after that. The reason is simply wear - the valves recede into the head as they and the seats wear - the change is more pronounced at first as things are bedding in. The danger of not doing this check is that things will close up so much that the valves don't close properly - the result is a burnt out valve / seat. Due to the fact that the tolerances actually close up with wear (rather than expand like on older non DOHC bikes), you will have no audible symptoms that its time to do the adjustment. Checking is quick and pretty easy, changing the shims is a little harder but straightforward with the right tools. If you are worried about doing it, you can go half way - do the check yourself and if you find it needs adjustment then puit it back together and take it to the dealer / a good bike mechanic to do the actual adjustment.
Mick, I don't like to question a gentleman of your obvious knowledge :D, but those mileages ? My handbook says 1st at 6,000mls (10k kms) thereafter every 12,000mls (20k kms) ?

Bueller, if you do decide to check a new valve cover gasket is rarely needed imo, tho' a timing cover gasket is if you go in there to turn the engine.

Mike
 

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Mick, I don't like to question a gentleman of your obvious knowledge :D, but those mileages ? My handbook says 1st at 6,000mls (10k kms) thereafter every 12,000mls (20k kms) ?

Ack! Damned fingers not working properly (or is it the brain)! You are right of course... I was thinking about servicing my jeep this morning and I do that every 3k :D

Old age - I tell yah!
 

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Discussion Starter · #8 ·
Thanks for advice.I think I will check them myself but get any adjustments done at the shop.bucket shim adjustment is one job I have I found time consuming and frustrating.I recently reassembled the top end of a GSX1100 in less time than it took to do the valve clearances on my VFR800 which ended up being a 10 hour nightmare job!That was my first attempt at bucket shim valve adjustment and maybe my last.The trouble is I also have little faith in the 2nd year apprentice that would end up doing the work on my legend.

The VFR800 problem was the clearances would change every time I put the cams back in and torqued the caps down and never really worked out why?
 

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Thanks for advice.I think I will check them myself but get any adjustments done at the shop.bucket shim adjustment is one job I have I found time consuming and frustrating.I recently reassembled the top end of a GSX1100 in less time than it took to do the valve clearances on my VFR800 which ended up being a 10 hour nightmare job!That was my first attempt at bucket shim valve adjustment and maybe my last.The trouble is I also have little faith in the 2nd year apprentice that would end up doing the work on my legend.

The VFR800 problem was the clearances would change every time I put the cams back in and torqued the caps down and never really worked out why?
After that 'carbon build up' BS I wouldn't go near that workshop, you sound more than capable to do it yourself imo. BTW, last time, I removed the metal coolant pipe from the top left of the head, otherwise it gets in the way a bit carefully replacing the valve cover. Coolant draining is not needed, only the water in the pipe comes out. Tape over the exposed hole to stop anything getting in there. A new gasket for this will be needed tho'. A new valve cover gasket should not be required & definitely no sealant crap for it. Removing the coils gives you more room to work too.

Good look, whichever way you go.

Mike
 

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Prior to pulling cams if thats the way your going, make a sheet with your clearences. Measure them prior to removing the Cams... As these always get tighter, you have a good jumping off point. Mike the old ones to see if they are still close to spec listed on the shim. This is where people make errors as they assume the shim coming out is still at spec which may/may not be the case.....It's simple math after that. You have a fairly large margin play which I would lean toward the upper 1/2 as these will eventually tighten up over time. Don't forget to mark your cams/chain so re-install lines up.

I agree that if your local shop is telling you carbon [email protected] parts from em...period.... I have never let some kid with a wrench ever touch any of my bikes....
 

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Get the tool rather than pulling the cams - its faster, easier and less error prone.
 

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Get the tool rather than pulling the cams - its faster, easier and less error prone.
Ah...where would the world be without a little diversity :D, I couldn't get on with the tool, found it too fiddly, no faster if there's afew shims to change - it's pulling the cams for me! No error problems...yet ;)
 

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Ah...where would the world be without a little diversity :D, I couldn't get on with the tool, found it too fiddly, no faster if there's afew shims to change - it's pulling the cams for me! No error problems...yet ;)
Its fiddly at first but you can develop a knack if you stick with it - for the novice it definitely help avoid potential pitfalls that come with removing cams ( dirt ingress, broken bolts, bolts dropped into engine, mis-aligned timing etc.) which is why I always suggest they go that route.

Talking of diverstiy - I have never flet the need to remove the water pipe! :D
 

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Unless someone can chime in otherwise, the aftermarket types are not much cheaper than the Triumph tool. I think I'd be tempted to buy the Triumph one as the quality would surely be good?
 

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Shims

If more than two or three shims need adjustment then I am firmly in the 'remove the cams school'. It is a very simple procedure and with care and a workshop manual handy most home mechanics will not find the procedure onerous.
The shims do not need replacement if adjustment is necessary, as mentioned before, simply take the shims to a competent automotive machinest. Tape the shims to cardboard with the measured clearance for each written adjacent (plus the fitted position), advise the machinest of the required clearances and he will simply surface grind the shims to spec.
Place the ground side of the shim into the bucket.
 

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I'm also in the 'lift the cams' school with lovecuba btw. I tried the tool & found it too fiddly, so sold it on. Some are ok with it & if there's just one or two shims need changing it may be quicker. I've not found fitting a new cam cover gasket needed yet or the use of the extra sealant. No oil leaks. (I have a gasket in hand but don't fit it unless I see obvious signs of damage to the original)
 
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