dual plugs

[michael]

I have a 1978 R100/7. The heads have been fitted for dual plugs. As a matter of fact the plugs are installed now. What is the next step for running the dual plugs? Do I need to change coils, adjust timing, etc?

[Kurt in S.A.]

Read what Tom Cutter wrote about dual plugging...be sure and read his intro. The basic concepts are fine, but some of it has been overtaken by events.

http://www.rubberchickenracinggarage.com/downloads.html

You certainly need to add coils (probably should change) and also need to adjust the timing to account for the quicker burning flame front.

Additional info here:

http://www.largiader.com/articles/ignition/

Kurt in S.A.

[chasbmw]

Bags of information out there....

Consensus on ignition timing is to have it near stock at idle, but at around 28 degrees at full advance with the advance point moved up to over 4000 revs.

Work out how you want to achieve this before you go and order coils, because if you go down the aftermarket electronic ignition system route, then you want to fit coils that are compatible with your ignition of choice.

Easiest and simplest is the alternator mounted ignition as supplied by euromotoelectrics in the US. They also have very detailed background and fitting instructions well worth a read.

http://www.euromotoelectrics.com/v/vspf ... o-v3.2.pdf