Hello fellow AIRHEADS,
Longtime lurker, I just joined the community today. My 1988 R100GSPD Bumblebee has remained stock for 27 years of ownership, but I never took the beast too far off road. Pick it up 4x in sand or mud and you will start looking for weight savings...
DURABOOST lithium ion battery shows 13.3V at the terminals. Rev to 3000 and the voltage spikes all over the place. 28V 30V? Scrambled numbers hard to read on multimeter. Collective wisdom here says it's the VR.
Yesterday, my AIRHEAD friend emailed this same question to you experts, and the team answered the call! "BP", Dave F. and others responded to my pal via AIRMAIL, and steered me in the right direction.
Thank you for the quick responses and suggestions for a solution. Voltage Regulator replacement in the mail.
-Chris "Big Bird" Ryan
Two suggestions....
1. Your OEM mechanical voltage regulator may have failed. (They often do.) I always suggest upgrading to a modern solid state version which can be both bought and installed very inexpensively and quickly.Â
* Here's one on eBay for about $25. Click Here
* Motorrad Elektrik also sells one for slightly more. http://www.motoelekt.com/charging.htm
Both of these units are plug compatible with the OEM unit and use the exact same mounting positions.Â
2. Stop using a digital voltmeter. These can be affected by spurious signals from the ignition. Basically the "spark gap generators" (what you call spark plugs) emit radio waves and some digital meters can act as receivers. If you've ever heard of the plan to explode a nuclear bomb above the Earth and destroy all the enemy's transistorized circuits through "EMP", then this is the exact same thing except on a much smaller, much more personal scale. Yes, your meter is quick, easy and fast... except in the presence of intense radio waves.
You might also check/replace your 5K Ohm spark plug caps, which are supposed to suppress this signal. You can find straight and 90 degree versions (sold by NGK) on Amazon. These are very high quality caps. Or, Motorrad Elektrik sells a complete plug wire kit with nice caps already made on.
Hope this helps.
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
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