by sportsterpaul » Sun Sep 20, 2015 2:03 pm
OK, poor Paul is confused again. I have always used the words "push" and "pull" to refer to what the cable does when you rotate the grip from its initial position. In this regard, that would be CCW (looking at the end) for the right throttle and CW for the left spark advance grip. By definition, if you switch the same grip from the right to the left, it changes from a pull system to a push system or vice versa.
Now my 1962 just happens to have a set of grips, that looks later model, just plain smooth black with a little groove at the end. The RH throttle is a pull type. That suits me just fine, since I have a 1976 Keihin carb on the bike, and it need to pull to open the butterfly. Now, I am told the only magneto bike that had spark advance is 1967 to 1969, since it uses the 29603-67 adapter plate ring down at the base of the mag. But now when I look at the 1971 parts book, I see the arm that rotates the mag is 29607-65 and is for 1965 to 1969. And yikes, there is another ring down at the base that is 29604-65A, and that is used for 1965 and 1966. I would love to know the difference between those two rings, but in any event, to me it looks to me that the only mags that rotate are 1965 to 1969.
So my question is when the carb went from push to pull, and when did the auto-advance circuit breaker come in? I see the flyweights start with a -64 part number but the parts book calls out usage from 1965 to 1970 across two part numbers. The auto-advance shaft however, looks to be 1965 to 1970, across three part numbers. The accursed cone ignition came in 1971.
OK, so to me this means that the mag was fixed from 1958 to 1964. The mag moved from 1965 to 1969. I assume the mag was not offered on 1970 bikes and cone ignition came in 1971. The circuit breaker moved from 1952 to 1970. Does this mean any handle bar set that has a fixed LH grip was for a 1958 to 1964 XLCH?
So once we figure out when the carb went from push to pull, it would nice to know if the circuit breaker and the mag both did advance and retard for the same direction, in other words, is pull advance on a mag and advance on a circuit breaker?
I put the auto-advance circuit breaker on my 1962 so I don't care, but I did have it set up with a mag at first. Let me go look, yeah, the LH spark advance is also a pull, when I rotate the grip CW the cable pulls.
BTW, I replaced the steel wire in the throttle side with a thin wire rope. That way I clamp on a little barrel to the wire rope and it pops into the 1976 Keihin like it belongs. The flexibly and years of oily life are so nice, that if I let go of the throttle at freeway speeds, the spring in the carb is enough to very slowly close the throttle.
I love how Patrick just uses the grip spiral that makes the bike work the way he wants. So is the OP trying to be "correct" or does he just want the mag to rotate when he twists the left grip?