I have a 1967 Honda CL90 bike here that belongs to an acquaintance that starts easily and runs well with one exception - very little power out of the stator. I can charge up the battery and it'll start easily and I can drive the bike around the yard . . . runs great. With a charger connected, it runs for a very long time but eventually quits in about five minutes. The bike has had the valves adjusted and the points adjusted and I need to find my strobe timing light tomorrow.
But with a multimeter attached to the battery, the voltage is falling or barely climbing even with the throttle above half throttle for long periods of time. The rectifier is good because with my multimeter set to AC volts, I can see small amounts of AC at the battery with the bike running - around .2 to .3 volts AC or so. It is an older battery about a year and a half old that has sat discharged for a while so I'm considering replacing it. It was also quite low on electrolyte.
I need to remove the fuel tank tomorrow to gain access to the stator wiring and check it for continuity, opens and shorts. It appears that a CT90 stator would fit but a comparison of the two stators wiring diagrams show that at least originally, the CL90 stator appears to have two lighting coils rather than all power coils as on the CT90 which will make a direct swap challenging.
Am I nutty for considering this stator swap?