hi everyone, I have a 1974 Z1 900 with a Boyer Bransden 500-1000 MK3 type ignition, it seems that I have low spark on all 4 cylinders and the plugs eventually foul out. The carbs have been rebuilt and cleaned and the bike spent a lot of time on the dyno.
I don't believe the coils are stock, they are yellow 2 post

- I was getting 9v to the coils so I put in a relay and ran a wire directly from the battery and now I get 12v
- it's been a while since I checked but both coils read 5 ohms
- testing it by turning the kill switch on and off produces a spark
- I tried one step hotter plugs from stock, the bike ran a bit better but eventually after hour of riding the plugs carbon foul (yes I did gap them)
- engine compression is good and even across all 4 cylinders
- I have not replaced the wires yet, but they were checked and all ok.

that's really all I can think about right now, but has anyone seen this happen with Boyer Bransden ignition?
my snow blower produces more spark when I'm trying to pull start it.. lol the bike is giving off a small blue spark.

thanks.

 

I have not used your current ignition before, but keep us informed. But the basics are always the same. Fuel, spark, ignition.