1 Aftermarket coils - utopia? Fri Aug 09, 2013 5:20 am
Erman
Gold member
Not trying to be a pioneer here, but as we know all OEM parts for the K's are an expensive deal.
The idea is to discuss and possibly find viable (read cheap) aftermarket coils. The motivation behind this, is that I've successfully upgraded the coils on my Seca to ones from Dyna, with almost 50% savings compared to OEM.
What's weird about the coils, is that BMW do not provide any resistance values. Haynes says N/A on the dual coils, and Clymer claims BMW do not provide testing procedures or resistance values. It's almost as if BMW knew they were into some black magic and didn't want others to know.
In this post, Rick says the HT coil shoud measure 40k Ohms:
https://www.k100-forum.com/t4798-it-s-not-the-alternator-it-is-the-2-3-coil?highlight=coil
Other properties of the OEM coils, are the mounting mechanism and three wire system (+/- and signal), firing order: 1-3-4-2, and I'm assuming 3 Ohm primary coil resistance. The firing order is probably what makes the coils need three-wire setup, but it also effectively disqualifies a lot of aftermarket coils.
Here is the price list for OEM material:
- Ebay (used): from 40$
- Motobins: 134,50£
- Motorworks (used): 38£
- Motorworks (new): 103,20£
Presumed applicable aftermarket candidates:
NONE
Why, oh why, BMW????
The idea is to discuss and possibly find viable (read cheap) aftermarket coils. The motivation behind this, is that I've successfully upgraded the coils on my Seca to ones from Dyna, with almost 50% savings compared to OEM.
What's weird about the coils, is that BMW do not provide any resistance values. Haynes says N/A on the dual coils, and Clymer claims BMW do not provide testing procedures or resistance values. It's almost as if BMW knew they were into some black magic and didn't want others to know.
In this post, Rick says the HT coil shoud measure 40k Ohms:
https://www.k100-forum.com/t4798-it-s-not-the-alternator-it-is-the-2-3-coil?highlight=coil
Other properties of the OEM coils, are the mounting mechanism and three wire system (+/- and signal), firing order: 1-3-4-2, and I'm assuming 3 Ohm primary coil resistance. The firing order is probably what makes the coils need three-wire setup, but it also effectively disqualifies a lot of aftermarket coils.
Here is the price list for OEM material:
- Ebay (used): from 40$
- Motobins: 134,50£
- Motorworks (used): 38£
- Motorworks (new): 103,20£
Presumed applicable aftermarket candidates:
NONE
Why, oh why, BMW????
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Bikes:
1984 BMW K1000RS
1984 Yamaha XJ750 Seca