what's wrong with the diode board?

**bryan** · #1 28 Aug 2003

there seems to be quite a few links re airhead electrics/charging circuits.
what's the "problem" with the standard diode board?
thanks

**Grant Johnson** · #2 29 Aug 2003

Pretty simple really - the boards made by "Wurth" for BMW are cheap quality and fail. The early ('70's) bikes had no great problems, they were made by Bosch and solid mounted for good heat dissipation.

In an attempt to prevent the failures BMW rubber mounted them, thinking it was vibes killing them. Didn't help, just made it worse as they overheated!

Buy a good board from Motorrad Elektrik - link on the links page - and install it and forget it.

You could also go for the complete upgrade "Omega" kit from Motorrad Elektrik, new rotor, stator, diode board and regulator, to bump the output from a miserly 280 watts to 400 watts, with excellent reliability. Beautifully made too.

If you go over all the grounds and make sure they're in excellent and clean condition, and put fresh heatsink paste behind the heat sink, you're good to go.

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Grant Johnson

Seek, and ye shall find.
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One world, Two wheels.
www.HorizonsUnlimited.com

**Andy Booth** · #3 29 Aug 2003

In my experience (50k r80gs) the diode board is no worse than you would expect from somthing subject to the heat and vibration at the front of the engine i,ve never had a problem. The main charging fault lies with the poor windings on the rotor 0 this is the most likely cause of a charging fault and can occur after as little as 20k. In either case both are cheap enough to replace yand fit yourself

**Sean Kelly** · #4 29 Aug 2003

Hi

Later model paralever GSs already have solid mounted diode boards - we have two bikes with over 50K hard, hot miles and no diode failure. Yet. Rotors have of course gone open circuit on occasion. Carry a secondhand one as spare to keep you going and don't forget to take a rotor removal tool.

The charging system upgrade looks really good though....

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Sean

**Grant Johnson** · #5 30 Aug 2003

FWIW - my R80G/S went 140,000 km with NO electrical failures. So it can be done, they don't aLL go, but as noted - most do have some failures.

Rotors, diode boards, starter motors regulators in approx that order.

------------------
Grant Johnson

Seek, and ye shall find.
------------------------

One world, Two wheels.
www.HorizonsUnlimited.com

**bryan** · #6 1 Sep 2003

thanks for the replies,
without seeing the updated components you wonder what's the difference.
agree with the rotor comments

**bryan** · #7 1 Sep 2003

Grant ....have checked out the link....now i see the diffence!!!