Probably just me but I don't recall any of the YF models not being followed by S. Maybe there were, but the data I have doesn't show it. The number stamping on this one is so faint toward the right side it may simply be the S just isn't visible...I can almost not see the last 0 there. The throttle body casting number is generally associated with the 216 carburetors, but Jon H (carbking) has said in the past those numbers apply to casting dates, etc and the measurement is the most important thing. Still, that is a throttle body for a 216. I've seen lots of them.
The 2100s is popular and in my opinion might be overpriced these days. I might blame the interesting (and to me unusual) allure of a manual choke, but almost all the YF models have shot up in price also. The popularity/scarcity has caused some people to swap parts and the throttle body is a common swap to "make" a 2100S that can be sold. I bought a 2100S a few years ago from a gentleman here which had been dropped and as a result of which the throttle body had been broken. In fact I just discarded that broken throttle body as I couldn't figure out how to fix it suitably. Today parts carburetors are hard to find. But the right throttle body is what is needed here. I have one but it would have to be repaired as the linkage side of it has been damaged and removed. Let's see if anyone else offers anything...
