I just bought an STS D3 and tore it down before running it. I Noticed That it had no Head shims. I went ahead and Broke it in like that and Ran it today first time. After a Few more Tanks I had it turn ON, Switch action that I've Heard about, is that from being too Far advanced and How much do you think I should shim it? I was Thinking .2 mm .008" I think thats the conversion.After awhile I was able to get it regulated back but Had to Really richen it up then had problems with it being too rich. Is a very fine line between the switch action and being too rich. Do you guys think the shims are the answer?