C72 from France

[Michael Stoic]

I admire your systematic approach with the mods and other updates! Will be interesting to learn from your long term observations of the modified charging system.

--
Michael

[sky.fred]

I can also drive with the headlight off, but I can't drive for long with it on. It's compulsory in France for motorcycles built after 1965, but it's also a safety feature for better visibility.

Yesterday, I went for a ride of about 40 km, with the headlight on (led bulb) and using the indicators.
On the way back, the battery was at its optimum charge level. So a priori it works, but I won't be able to check it over longer distances for the time being, as I'm in the process of dismantling the bike to change the selector drum.
I didn't make it up, I found this connection on the internet. And it makes sense because Honda didn't have a regulator in the 60s, so they used light bulbs to regulate. So there were two charging circuits: a less powerful one for daytime, with headlights off, and a more powerful one for nighttime, with headlights on. By coupling the two, it's logical to have an alternator that delivers more power, and the regulator will solve the problem of excess load. The only drawback, though not a major one for touring, is that the alternator operating with its two circuits will consume a little more power from the engine.

New régulator


Connecting the yellow and pink wires

[sky.fred]

The bike is back on the operating table to try and fix the reverse gear selection problem.
No particular problem disassembling the peripheral components, but a 20 mm Spanner Crankshaft Nut Tool is essential, and to remove the alternator, a 16 mm bolt with a 1.5 pitch. I didn't have this bolt, but I remembered that on Honda 125s, you can remove the alternator with a wheel axle, and I had this in my stock.

Turtle-on-back method ....





And that's where it gets tricky!
The 24301-268-000 drum that's supposed to solve my problems doesn't fit on my gearbox. Apparently there are two models of gearboxes and several models of drums, but the axles and pinions seem to be identical, so it's hard to find your way around.
Which also doesn't explain why my drum selects gears in reverse.
The good news is that the gearbox shows no signs of wear, which seems to confirm that the engine has only a few miles on it.

[Geoff Hastings]

I’m as puzzled as you are about the sequence of gear selection. If you just rotate the selector drum by hand do the gears actually select in the normal correct 1 N 234? This is just a guess but, could the selector mechanism levers have been assembled wrongly or be bent. It’s a few years since I had mine apart so can’t quite remember how the levers rotate the selector drum.

[sky.fred]

I've checked and rechecked, the selector mechanism is correctly mounted.
I'm wondering because on the video below, it's a C72 exactly like mine and it seems to me that at the beginning of the video, it shifts into second gear by pressing the selector
https://www.youtube.com/watch?v=D1rHBE9Ba0Y
Didn't the first C72 models have a selection like the English bikes but with the selector on the left? I remember that the Kawasaki 750 H2 had a N12345 gear order.
The problem wasn't so much the reverse selection - I got used to it in the end - as the fact that in 4, if you press the pedal shifter gear, you're in neutral.
The groove in the selection drum has no stop but goes all the way round, which explains why you can do N1234N1234 etc. indefinitely, but I'm surprised there isn't a stop in 4?
Can a C72E owner (from 1963 but the year could be earlier on the video, it's a 1960) motor 72E 325XXX tell me what the order of his gearbox is? (This is not an export model but a bike originally sold in Japan).
I'm continuing my research but it's irritating me not to be able to find how and with what parts to have a 1N234 selection as it seems on the CA72/77.

[Geoff Hastings]

I watched the video and he definitely selects 1 by pressing down on the gear lever and when he returns he lifts the gear lever up from 1 to 0 the same as my C77 and C95

[Geoff Hastings]

I could only find this one photo of the selector on my C77, it’s probably not a lot of help.