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Alpina resistor


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Hi, Ellessemo -

Welcome to the Bultaco forum.

Just checked a couple of mod. 85 resistors with analog multimeter. They both measure 4.7 ohms across the tags of the actual resistance; one measures 22 ohms, the other 25 between the spade terminal on the green wire and the frame mounting bracket (earth/ground) i.e. with the diode in circuit.  Can't vouch for the accuracy of my meter, mind you........... HTH

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Thanks very much for taking the time to measure your resistors, Lorenzo.  I'm having a hard time understanding what you wrote because I've never seen a brake light resistor and don't know what you mean on the tags and terminals.  And I didn't know a diode was involved at all.  I posed the question because I can't seem to find a working resistor for sale and figured I would find out what the resistance is supposed to be then mount a wire-wound resistor so I can get my bike running.

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Resistor is a proprietary Femsa item RSA1X-7 (Bultaco pt. # 85.21 - 217).

If you simply want to get the bike running without stoplamp function,  just connect the green wire to a reliable earth/ground. This will enable the mag. to produce a spark.


Edited by lorenzo
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These resistors were o.e. fitment on several Bultaco models supplied with direct AC lighting, including many of the Sherpa ranges, and were I suspect relatively common. Could maybe have been used by other makes, too. Unfortunately, the availability of genuine Femsa parts has long been in decline.

You don't state your location, but as with most other old bike parts, eBay is your friend. Leastways, that's where mine came from...........

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