Valve Shims

AnonymousUser1

AnonymousUser1

Elite Member
Posting something related to Ducatis - SHOCK!!!

Around three years ago, I was going to do a valve shim check on my old ST2. I was at the point of measuring clearances on the vertical cylinder and knew that both opening and closing valves needed shimming on the vertical cylinder. I hadn't got around to looking at the horizontal cylinder. Then, I was knocked off my Monster and that put the end to that game!

Now, I want to finish sorting the ST2 out and get it back on the road, at some point.

As it is a pain to do a lot of standing up, I thought about getting Richard at Lougi Moto to do it for me. I've just spoken with him, and he is very stressed with lots of work and no time! He would need me to either put it back together, tax and insure it to ride it to him, or pay someone to transport it to him, but this would mean that I don't need to bother to put it back together, tax, insure, MoT it, and any other shit that I've forgotten!

Or, I could just get on with it myself. I've got space, and it is on a bike stand. I've checked and there is no problem with getting shims - even though the bike is over 20 years old!

So, do I just get on and do it myself? Actually, I have just spoken with a bike transport guy that knows Lougi Moto and had taken bikes there before. He said £50 each way. That would mean not farting about putting it back together, but by the time that Richard could do it, I could do it myself. Anyone shimmed a 2-valve?
 
Do it yourself, I would & do. It’s not difficult just very fiddly, remember to keep the split collars separate so they go back on the same valve they came off and, very importantly make sure the piston is at TDC to stop the valve dropping into the cylinder 😱.
 
West Cork Paul said:
Do it yourself, I would & do. It’s not difficult just very fiddly, remember to keep the split collars separate so they go back on the same valve they came off and, very importantly make sure the piston is at TDC to stop the valve dropping into the cylinder 😱.
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Thanks and that is good to know. I don't know if I caught a very stressed Richard @ Lougi Moto, but he said it was a bastid - especially if you drop a valve into the cylinder. As it all needs to be done @ TDC, I could not see why dropping a valve could occur - unless to change a shim, you need to move the piston out of the way to lower the valve?
 
PerryL said:
Thanks and that is good to know. I don't know if I caught a very stressed Richard @ Lougi Moto, but he said it was a bastid - especially if you drop a valve into the cylinder. As it all needs to be done @ TDC, I could not see why dropping a valve could occur - unless to change a shim, you need to move the piston out of the way to lower the valve?
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All at TDC, no worries dude (y)
 
PerryL said:
Thanks and that is good to know. I don't know if I caught a very stressed Richard @ Lougi Moto, but he said it was a bastid - especially if you drop a valve into the cylinder. As it all needs to be done @ TDC, I could not see why dropping a valve could occur - unless to change a shim, you need to move the piston out of the way to lower the valve?
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Take a look at the parts diagram here


Particularly part Nos 17,18 & 19. 17 is the closing shim, 19 is the opening shim, 18 is the pair of half collars which sit in a groove on the valve stem. To remove the closing shim in order to replace it with one of the correct size you need to remove the 2 x half collars but as soon as you do there’s now nothing holding the valve in place and gravity will have its effect. With the piston at TDC the valve can only drop about 1mm if that. With the position not at TDC the valve can drop however far the piston is down the cylinder, certainly far enough that you can no longer get the top of the valve stem to replace the shims.
 
West Cork Paul said:
Take a look at the parts diagram here


Particularly part Nos 17,18 & 19. 17 is the closing shim, 19 is the opening shim, 18 is the pair of half collars which sit in a groove on the valve stem. To remove the closing shim in order to replace it with one of the correct size you need to remove the 2 x half collars but as soon as you do there’s now nothing holding the valve in place and gravity will have its effect. With the piston at TDC the valve can only drop about 1mm if that. With the position not at TDC the valve can drop however far the piston is down the cylinder, certainly far enough that you can no longer get the top of the valve stem to replace the shims.
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What I don't get, is why would you NOT have the piston at TDC if you were messing about with the shims. Is there any need to not have the piston always at TDC? This is given that I am in no hurry and would get the vertical cylinder sorted out completely, before moving on to the horizontal one - given that I have lots of other transport and can fetch down to Riders more than once for shims. Their coffee shop is no hardship!
 
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