question - dimensions of factory air filter.

JC
Obviously pix of 71...
20M3S engine= hose from cam end
intake mainfolds early 6 fin style 30/28.5mm
BUT air filter mounted key bracket started in 71 (IMO...wires should go inside frame rails)
bad bad bad #2. Install(and remove) air cleaner always/only from timing side.

My bike is a '73 roadster (originally) but has been configured as a Fastback for 10 years - no change to the filter unit It has the standard plain type of plate (no snorkel) with the air-cleaner mounted key switch. The filter assembly is identical to the one on my '71 roadster OTHER than the lack of they key switch on the plate. The page posted by Joe is the same as the page I was referring to - I was thinking it was in the owners manual as well but I agree that if you have a snorkel, you could not slide the filter in/out out as shown.

I just realized that pic shows it coming out on the primary side - I've always removed it from the other side.