I'd like to get some opinions about the optimum kick starting ignition advance number for a normal road going twin or Comet. (close to factory size carbs, 7or 8 to 1 compression, 140 to 190 pound 65 to 75 year old kick starter pusher, magneto replaced by a coil system). I know the factory provided the ATD and Lucas distributor which were theoretically set to 4* BTDC static timing, and I have heard this figure repeated many times on this forum and elsewhere.
I am asking since the programmable ignition I am using has this curve as its default setup:
It is a multi spark system with three sparks. As you can see, at kick start speeds the first programmed spark occurs at 12 BTDC, the second at 5, and the third at 0. I don't have too much trouble kick starting my Rapide, generally 2 or 3 kicks from cold and first kick when warmed up. I very occasionally get a pop through the carb when cold starting. I can easily change this and I may reprogram to a lower first spark when I get up north to the summer place where the bike is hibernating for the winter, but I hope I can get some opinions about whether it makes any difference that the starting advance at very low engine RPM's is 8* higher than the factory recommendation. I can change that and not affect the rest of the advance curve.
As a related question, what is the average kickstart RPM, given a good stroke with follow through?
We have 3 twins running on this system now.
Ron
I am asking since the programmable ignition I am using has this curve as its default setup:
It is a multi spark system with three sparks. As you can see, at kick start speeds the first programmed spark occurs at 12 BTDC, the second at 5, and the third at 0. I don't have too much trouble kick starting my Rapide, generally 2 or 3 kicks from cold and first kick when warmed up. I very occasionally get a pop through the carb when cold starting. I can easily change this and I may reprogram to a lower first spark when I get up north to the summer place where the bike is hibernating for the winter, but I hope I can get some opinions about whether it makes any difference that the starting advance at very low engine RPM's is 8* higher than the factory recommendation. I can change that and not affect the rest of the advance curve.
As a related question, what is the average kickstart RPM, given a good stroke with follow through?
We have 3 twins running on this system now.
Ron
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