Setting tappet clearances in situ is not my favourite job David. I also find it is very easy to make an error. I nowadays have the habit of setting them all, then making (at least) a second pass to make sure they are all where I thought I put them, which often flags up the need for some minor re-adjustment. I also try to re-check them after a bit of running. That's about all my back can take...
Could it be that your block to crankcase gasket / joint has "settled" a little over time? Likewise I go around the block fastenings with my spanner several times after making the joint and at least 24 hours later, as some compression can occur (depending on what you make your joints with, of course).
Could it be that your block to crankcase gasket / joint has "settled" a little over time? Likewise I go around the block fastenings with my spanner several times after making the joint and at least 24 hours later, as some compression can occur (depending on what you make your joints with, of course).