Triumphrat

stu · 01-20-2008

I have a (gulp, dare I say) BSA 650 Lightning(along with my 02 Sprint and 02 Bonneville) with Boyer ignition. The bike is running 12v coils wired in series to get 6v inputs as per Boyer instructions. I have been told that this setup is severely reducing the HT voltage going to the plugs and I should get 6v coils. Is this correct? Anybody out there running Boyers like to comment? I'm still rebuilding this bike and haven't run it yet.
Cheers
Stu

Mecchanica · 01-20-2008

Which Boyer system do you have?
Doesn't really matter which Boyer, I suggest you put it on ebay and get a Pazon or a Trispark.
The Trispark comes from Australia and is a singlefire system....each plug fires independently, no wasted spark. Spendy, but worth it. Supposedly the twins system is ready or nearly ready for delivery. The one for the triples is rapidly becoming the standard conversion for those bikes.

OzBloke · 01-20-2008

Stu,
If your battery and charging system are in great shape, your plug leads and plugs are perfect and not resistance (or suppressor) type, the BSA "may" run OK with 12V coils. If any of these is less than perfect or over time degrades to a poor condition, you may (read "will most likely") have trouble with 12V coils. Delivering 6V (in effect) to a 12V coils is like trying to run a 12V lamp with 6V - low output.

Personally, I tried the 12V coils, and with a weak "standard" lead-acid battery, had heaps of trouble. As soon as I went with 6V coils, and an AGM maintenance-free battery, problems gone.

Pete