Really good clarification there Kirk. Like to go a little further, if you don't mind.
If you'll look at the rear fender on the 1st bike in this photo and compare it to the rear fender on the 2nd bike, you'll notice quite a difference with the CL77 being more full. The CL engines are mounted within the frame, whereas the CB engines are hung in the frame (making the engines part of the frame). Within the 250 & 305 line of engines, there are what's called the "Type 1 & the Type 2" engines. The Type 1 engine has 2 sets of point, 2 ignition coils and a 180 degree crankshaft. Where the Type 2 engine has 1 set of points, 1 ignition coil and a 360 degree crankshaft. Like Kirk said, the CA engines have 1 carburetor and the CB along with the CL engines have 2 carburetors. The kick starter on the CB72 & 77 engines, kicks forward and down. All the others operate like a traditional kicker. To the best of my knowledge, the CL72 & 77 are the only ones of that style of engine, that don't come equipped with an electric starter ( the crankshaft isn't even drilled with the oil passage to lube the starter clutch on the crankshaft (if you were to put the setup on a CL engine, the starter clutch with burn up with a lack of oil.). Hope I have helped and not hindered.
