I've just been doing the valves on my 530. It's a long story but my local (2hr round trip) KTM dealer supplied the wrong diameter shims. It turns out he'll have to order the correct ones (which are the same for all current KTMs).
As it has taken 2 weeks to get to this stage and it will take another week for the right ones to arrive I tried 'adjusting' the existing shims. I made a simple jig to hold the shim and removed a little material with a belt sander from the valve side of the shim. Trouble is they are not as hard as I thought and even one second in contact with the belt has removed too much. The exhaust ones worked out fine and they are both on the top limit (0.17 mm) but the inlets are both about 0.05/6 mm above the top limit (0.2 instead of 0.15mm).
I've put it all back together and it is running fine. What are the potential problems of having too large a clearance?
As it has taken 2 weeks to get to this stage and it will take another week for the right ones to arrive I tried 'adjusting' the existing shims. I made a simple jig to hold the shim and removed a little material with a belt sander from the valve side of the shim. Trouble is they are not as hard as I thought and even one second in contact with the belt has removed too much. The exhaust ones worked out fine and they are both on the top limit (0.17 mm) but the inlets are both about 0.05/6 mm above the top limit (0.2 instead of 0.15mm).
I've put it all back together and it is running fine. What are the potential problems of having too large a clearance?