ORIGINAL: asmund

Yepp, I can confirm that W8ye are correct. I have used the dot in line with the cam followers on ASP 61 fs, 91 fs, 180 fs even YS 110. I think this is a kind of universal method of setting the timing. The dot can of course point downwards too, but not 90 degrees too the crankshaft, because then it will be off by a tooth or so. It still must align with the pushrods and therefore it is more easy to just line it up right under the camfollowers. Piston must be at TDC in either cases

Edit: I think you are correct too Jens but it is a little harder to be spot on when the dot is pointing down. If the dot is at the tip of the purple arrow in your drawing instead of in a 90 degree angle to the shaft then it will be the same as the above method. I have tried the "dot down" method but found it much harder to get the timing accurate that way, it only takes just a little bit of wiggeling of the crank shaft to be off. It may seem like the dot is pointing straight down, but if the piston really is at TDC and one examine carefully one will se that the dot actually lines up with the cam followers/pushrods . . . . .