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Today i made a TDC finding tool and degree measurement tool.
i have downloaded, printed off and studied the "Timing" information by "flamingoesd" in jd yahoo grps
Now, my questions and observations.......
1. Timing ignition is done off the front cylinder ?
2. I would appreciate hearing your experience the best BTDC measurement ? (i'm using domed Venolia pistons, so i suppose that is a more or less equivalent of the "Rici head" ?) Dan Margolien wrote me he has his 26JD set at 5/16" BTDC i have heard 3/8" but do not have 1st hand source such as from Dan.
3. for full advance, is the timer turned forward ? (CCW?)
4. i am used to setting ignition points just opening at the BTDC position. Would points just opening be correct procedure when measuring setting ignition timing by BTDC ?
5. i have also read the procedure to time ignition in the 1927 Rider's Hand Book. i had read it probably well over a year ago..... long enough that i forgot i read it.
A. As you all know, the Hand Book discusses simply and clearly timing ignition with timer set in full advance position, does not state which direction timer is moved to be in full advance direction?? But then, i can look at which way the narrow end of cam moves relative to the heel of the points cam.... ?
B. Instructions go on to say, compound gear is removed.
C. "turn generator in direction in which it operates (to left) (this is counterclockwise?) until the narrow end of the circuit breaker cam has separated contact points about one half their full opening."
D. then fit compound gear.
E. i realize this procedure has to work, it has been used thousands of times.... the contact points being separated "about one half their full opening" got me going. Specifically, it the word "ABOUT" that creeps me out..... it seems relying on the general alignment of the marks on the gears and the points "about" half open creates a strong possibility for an incorrect setting relative to BTDC....
F. i guess i could measure the distance between points closed and fully open, divide the distance and then guess at "about one half"might be.... and i guess i could measure the btdc of the piston when the marks are aligned and the points are "about" half open.
Anyway..... i guess i am writing all this out for 3 reasons..... 1 is that i have a clear understanding what the procedure is and 2 someone will tell me my understanding is correct or incorrect and 3 just tell me what the TDC/BTDC measurement is. The more i think about this, i realize it might be possible the only BTDC setting there is is the setting at which the engine starts easily and runs without knocking or overheating......
20160305_150445.jpg20160305_165514.jpg20160305_150345.jpg)
i have downloaded, printed off and studied the "Timing" information by "flamingoesd" in jd yahoo grps
Now, my questions and observations.......
1. Timing ignition is done off the front cylinder ?
2. I would appreciate hearing your experience the best BTDC measurement ? (i'm using domed Venolia pistons, so i suppose that is a more or less equivalent of the "Rici head" ?) Dan Margolien wrote me he has his 26JD set at 5/16" BTDC i have heard 3/8" but do not have 1st hand source such as from Dan.
3. for full advance, is the timer turned forward ? (CCW?)
4. i am used to setting ignition points just opening at the BTDC position. Would points just opening be correct procedure when measuring setting ignition timing by BTDC ?
5. i have also read the procedure to time ignition in the 1927 Rider's Hand Book. i had read it probably well over a year ago..... long enough that i forgot i read it.
A. As you all know, the Hand Book discusses simply and clearly timing ignition with timer set in full advance position, does not state which direction timer is moved to be in full advance direction?? But then, i can look at which way the narrow end of cam moves relative to the heel of the points cam.... ?
B. Instructions go on to say, compound gear is removed.
C. "turn generator in direction in which it operates (to left) (this is counterclockwise?) until the narrow end of the circuit breaker cam has separated contact points about one half their full opening."
D. then fit compound gear.
E. i realize this procedure has to work, it has been used thousands of times.... the contact points being separated "about one half their full opening" got me going. Specifically, it the word "ABOUT" that creeps me out..... it seems relying on the general alignment of the marks on the gears and the points "about" half open creates a strong possibility for an incorrect setting relative to BTDC....
F. i guess i could measure the distance between points closed and fully open, divide the distance and then guess at "about one half"might be.... and i guess i could measure the btdc of the piston when the marks are aligned and the points are "about" half open.
Anyway..... i guess i am writing all this out for 3 reasons..... 1 is that i have a clear understanding what the procedure is and 2 someone will tell me my understanding is correct or incorrect and 3 just tell me what the TDC/BTDC measurement is. The more i think about this, i realize it might be possible the only BTDC setting there is is the setting at which the engine starts easily and runs without knocking or overheating......
20160305_150445.jpg20160305_165514.jpg20160305_150345.jpg)