The 12x22 is incorrect. The pins between the case and the cylinder are 12x15 and between the cylinder and the head are 12x18.
Makes sense. Strange, though, that my ancient parts catalog AND the current Honda parts fiche all say 22mm. I also find it odd that I've never noticed a size difference. I KNOW I've pulled 18mm's from the case to cyl. side (not on the current project, those are deee-stroyed). Does it make a difference if it fits? Should I grind off 3mm from the ones I have?
Ron- I seem to remember you looking for pins in a post recently. Were these the ones? Did you modifiy what you had or buy new? And if you did get new did you think to throw a caliper on it (or notice that it is actually shorter)?
Yes I have an ancient parts book too, stops at K2, same thing. Yes these are the knockers i was looking for/at. My original ones had been separated from the engine years ago, probably (some assurdly) destroyed in removal. But I have a small stash of them. I ordered 22mm fromMotogrid, they showed they had them, but then backordered them with no expected date of release. Remember my engine came apart 10+ years ago. Going together, the cases, cyllinders, and head were all from different sources.
So I measured the holes themselves. You have to measure down the side of the holes as they have a taper in them. If you measure to the center of each hole you'll get an erroneous reading that is too deep. 22s would have never been short enough and would have jacked the head up off the cylinders. My final decision was to use ones that for instance set all the way down in the cylinder with about 4 mm sticking up above the head cheese. The receiving hole in the head was no more than 6mm. That should be enough, we'll see. I'm pretty sure I measured them at 18mm.