Since last season my '82 R65 LS hasn't been charging every time I go for a ride. Thankfully bump starting is a cinch. I checked the connections to the stator etc and all looks good. All new parts in there too. After similar issues on my Moto Guzzi that turned out to be a toasted battery I'm thinking this might the same issue with my R65. I know the same battery has been in the bike for many years so it wouldn't be any surprise. Now it's just a matter of looking up what the replacement is and try that. The Goose was solved with a new one.
Hello Mike, Euro Motoelectrics sells Rick Jones book “Classic Boxer Charging”. It’s a great little book that walks through diagnosing charging issues. Seems like most airhead owners wind up having one of these books. EME gets $30 for it, but I think it’s worth it.
My check list...
1) Battery. As you noted, batteries may seem OK coming out of storage, but unless they were pampered over the winter then there is always the chance. My test is this: charge the battery slowly for 24 hours, remove the charger, turn ON the headlamp for 1 minute, then use a voltmeter to get a Voltage reading across the + and - terminals. This reading MUST be above 12.2 volts. If you see a reading like 11.8V or even 12.0V, then that battery is gone. An optimal battery should be 12.3V or higher.
And as always, check the battery connections for terminal corrosion at BOTH ends of BOTH cables. I highly prefer the new, sealed, AGM batteries because they don't leak acid, which reduces corrosion issues at the battery terminals.
2) Brushes. Replace the alternator brushes. The length of the carbon decreases over time, which in turn decreases the spring pressure against the slip rings. Poor brush spring pressure equals poor connectivity.
3) Voltage Regulator. Replace the worn-out, 50yo, OEM mechanical voltage regulator with a modern solid state device (which has no moving parts to break or come out of adjustment). If you don't want to buy the one from Motorrad Eliktrik, then Here's One on EBay already set up for AGM's for $24.
Hope this helps.
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
Thanks for the info.
Yeah...it's been on a trickle charger for days and it still only showed 11.3V so I'm sure it's pooched. I know it's been in the bike for many years so no surprise. Does anyone know a common brand battery for this bike? My local supplier does not even show this bike in their system. Thanks.
https://share.google/aimode/VJDUMPjoFTQelba2t
Looks like YTX24HJ-BS or YT19BL-BS are the most suggested sizes, and AGM to prevent acid leakage.
> There is a common battery used in lawnmowers and Harleys called the "U1". This battery measures correctly on the outside dimensions, but the terminal positions are reversed.
> Most new batteries should be trickled for several hours before use. An AGM may require a higher charge voltage than a basic lead-acid battery to maximize their longevity. Be sure and read the small slip of paper inside the box.
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
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