Hmm...by chance, does your C3 gear have a cast-iron, flanged insert that fits into the center of the gear? If so, the flanged side of it acts as the separate toothed washer-bushing, and this side of it should be set against the circlip. This was found in some 750F3 engines.
The picture in the book was taken as I tore down a 750F0 engine (the same one shown in the "Remove Engine" chapter). In the late F2, and I have also seen in the K8, the bronze bushings and center bearings were sometimes replaced with flanged cast-iron versions, eliminating the separate bronze toothed washer.
Gammaflat knows something about that one... 
). In those cases, the flange of the flanged bushing sat against the circlip, instead of the separate toothed washer.
Okayyyy, now I'm getting somewhere! Thank you Mark!
So yes, both my C2 and C3 gears have the flanged bushing/insert.
Now the next question becomes this: does the flat side of the circlip point towards the flange of that insert? Or does the chamfered side of the circlip point towards the flange of that insert?
There, NOW you've got it!
The flanged side of that iron bushing takes the place of the bronze toothed washer, so flip that one 'round and you should be on your way!
I would estimate that to be a K8 gearbox.
Ugh, Mark you didn't answer the question I need the answer to!
I need to know about the circlip.
Does the flat side of the circlip point towards the flange of that insert? Or does the chamfered side of the circlip point towards the flange of that insert?
Chamfered side to the bushing, absolutely! The 'straight' side of it does not let oil leak in between this clip's face and the bushing, which is needed to help keep the clip cooler than the bushing so it won't try to 'climb' or warp, and move.
You'll note that the gear next to it on the clip's side (C2) stops about 2mm away from the clip when the shift fork moves it in that direction, too.
Awesome thank you! Exactly what I needed to hear, because my thoughts were to install it the exact opposite!
My next question...
The circlip that comes after C4 (going towards C1), what is the orientation for that circlip? Does the flat side of the circlip point towards C4 or does the chamfered side of the circlip point towards C4?
Same goes for the thrust washer - does the flat side point towards C4 or does the chamfered side point towards C4?
For this one: the chamfered (rounded) side of the clip goes toward the thrust washer, because it can wiggle a bit when the gear next to it is spinning and a shift to it occurs. When you get this shaft back into the crankcase and the forks engaged you'll find that the sliding C4 doesn't quite press up against this clip when in actual use, or if it does, just barely. Since it can't rotate, it doesn't pose any troubles like trying to 'unwind' the clip out of the groove.
The rounded side of that bronze thrust washer should go toward the C1 gear/bushing here, because the bushing in this gear is smaller diameter than the thrust washer - plus, they wiggle against each other some. The 'philosophy' here is: (after 200,000 miles or so, maybe?) that thrust washer might gall against the bushing inside the gear if the flat side was there, so a trifle more oil will work its way into that joint if the rounded side is pressed up against it.
The caveat here, in the later engines, is: this bushing was often made of cast iron, or included into the C1's inner bushing as a flanged bushing when it was made from cast iron (I have seen it both ways), so then the oil (and rounded side) needed to be in between the circlip and the bushing face, lest it friction-weld itself to the clip over time (only a long roadrace could accomplish it, but Honda was uber-conservative in those days). I know of just one guy (in Colorado)_ who worried enough about this with his 750F2 racer that he hand-lapped both sides of both the circlip and the (in his) cast-iron thrust washer for 'better oiling'. After we talked about it, he just bought bronze bushing and thrust washer and replaced them, instead - the bronze is a MUCH better bearing on steel, especially at speed. The switch to cast iron was done to save a few Yen to help keep the cost of the 750 competitive at the time.
But, all this said and worried about: sometimes these got assembled wrong at Honda! I've seen it in several engines that came to me: our own member Gammaflat had this happen in his (K6, I think it is), and it lifted the clip out of the groove for the C2 gear(!).
