Is there a way to mill down the Triumph heads so they can get 9;1 with a flatter piston like the Norton and eliminate the need for the twin plugs ??? I have two 650s and the one 750, and if I have to go through them in the future I would like to make them the best they can be with a practical amount of time and money.
if you have the head off, rob hall will twin plug it for $100.
use any EI with dual lead coils that add up to the correct resistance.
retard the spark to 30 BTDC.
vastly easier than milling the head and then dealing with custom pistons, pushrod tubes, pushrods, and valve to piston clearance.
ive got two T120s with twin plugs. my older one has been trouble free for 36 years. the next one i do will be 10 to 1 so i can see just how high i can go. you cant see the modification with the tank off, and if you dont like it you can just screw a plug into the holes.
no rocket science here