Carb Cap Crisis

[Sidecar Bob]

Being involved in both the 4 cylinder 'Wing community and the the CX/GL500/650 community I find it interesting that the GL1000 was the flagship model in '75 but then upgrades to newer tech basically didn't happen until the GL1100.
- The GL1000 had points until the end of production '79 while the CX500 had CDI from first production in '78. GL1100 had TI from start in '80 but that system didn't find its way into the CX family until the '81 GL500 and CX500E (the CX500C didn't get TI until '82).
- GL1000 carbs had buttons in the tops until end of production while CX500 carbs had solid tops (similar to the GL1100's with the bumper on the slide's shaft) from the beginning in '78.
There are a few other things that don't come to mind off hand but you get the idea.

Anyway, my point is that if they wanted to they could have had solid carb tops from at last '78.

[Lucien Harpress]

Yeah, that is odd. I was going to I say something about Honda not wanting to change up an established model in the middle of a production run, but then I remembered that small, minor changes of a model nearly every year was something Honda did ALL THE TIME.

[Sidecar Bob]

The GL1000 had an electric fan in '75 but the CX/GL500 bikes came with mechanical fans mounted on the front end of the camshaft (the water pump is on the back end - perhaps the load from those explains why they used a triple row camchain) and that family didn't get electric fans until the 650 models in '83.
I think I may have figured that out, though. The alternator stator armature of the CDI CX has the same footprint as that of the GL500/650/1000/1100/1200 and probably a lot of other models (likely including other brands too) but the CDI is powered/triggered by special windings on the stator that take up a lot of room on the armature so there is only enough room for the windings that power for the main electrical system to produce 150W. My theory is that they didn't think there would be enough to run something like 85W of lighting plus the fan (as needed) and still keep the battery charged (especially in stop & go traffic when the RPM is low and the brake lights - another 46W - are in use much of the time and the fan is most needed) so they opted for a mechanical one instead. When they changed to TI and a stator that was entirely devoted to powering the electrical system for the GL500 and CX500E in '81 (and the CX500C in '82) the 650 version was probably already i development so they just left the mechanical fan on the 500 engine for the rest of its production life and made the change with the 650 engine.

Another example is that the '84-86 CB750SC (Nighthawk S) had CDI instead of TI, although its was powered from the bike's 12V system.