Shims can be sanded as long as you keep them flat so setting 2-valve shims is one spot where I set them as a certain measurement vs in a range. Keep in mind the closer clearances are set to zero , ***without preload*** the longer the clearance lasts as well as less wear in the system. If you change 1/2 rings expect your clearances to be .03-.06mm looser shortly after you do the work. So factor the extra break in on new 1/2 rings. If the existing 1/2 rings are serviceable and you re-install them in the correct (upside/downside) orientation, they are BETTER than new 1/2 rings.
If the 1/2 rings are broken or excessively worn they need to be changed, if not you do more harm than good. If you can not read 1/2 ring wear you will be better off buying MBP collets as they should be impossible to install upside down, though I do see them installed incorrectly too.
Valve recession is normal on all engines as long as it is not excessive. You will probably not find many engines that do not wear in from the time they are built so consider it a part of break in. On a 1000 motor I would expect the heads to be broken in somewhere around 22,500 miles (third adjustment). This is normal across the range and after about that amount of miles if the valves have been taken care of we start to extend service intervals. Note: if you cut the valve seats you re-start break in on the heads so racers keep that in mind or anyone who has had valve guides changed.
Rare cases (my 851) had soft seats where they never stop sinking and you usually run it until you have no more shim options and have to change the seats. I can count on one hand the amount of bikes I have run into with that issue...... actually it was just mine:frown2:
If you are doing the work do not be lazy and set them right, the checking spec is for dealers trying to not adjust valves (more money not adjusting most of the time) or those looking to not do the work. by the fact you are there you are trying to do the job right so set them properly and the valvetrain will treat you right for many miles to come. .... YOU CAN DO IT!
We set them at .10mm intake
.13mm exhaust
closers are set to zero with no preload, very important that there is no preload. If you are not sure set them to .01mm and the wear should be minimized.
If you are not comfortable setting them , pay some one to do it AND TEACH YOU HOW. Sorry for the caps but it is always best to emphasize that it can be done and should be done right otherwise you might as well not do it in the first place.
We have faith in you. :wink2:
Thanks for this detailed response! It gave me a lot to think about and raised a few questions too.
Based on your suggestions and the fact that I can sand those shims, I can aim for a specific measurement. This makes the end goal a lot simpler.
Can you explain what preload means in this context?
I am measuring the closer clearance using the unloaded/loaded method. Once I figure out the measurements, I try to double check the closer clearance if its in the range of my feeler gauge (0.04mm is the lowest I can go) . FYI, I didn't remove the belts when I made these measurements. Oh, I also double check that the cylinders are in TDC. I go with the cam's timing marks for the horizontal cylinder and then rotate the crankshaft 270 degrees anti-clockwise for vertical.
And thanks for heads up about the half-rings, will see how they look when I go over the valves again this weekend.
The part about about the engine-breakin was quite informative, I didn't think about the valve-seat wear and the break-in process. More food for thought. Hopefully, my vertical cylinders is not a total softie!
I really like working on this bike, so I don't mind going over things a few times. Also, its not my main means of transport. So that helps haha
My humble w650 is handling that duty now
A big thanks for your optimism and looking forward to your response.