Ignition timing

[frankfast]

When I lined up the dots on the gear that drives the ignition cam with the dot on the oil pump gear my 350 Scrambler wouldn't start or run so I lined up the slash (off one tooth) mark with the dot on the oil pump gear and it started second kick and runs fine. I've been told that the slash mark is for 450s only. Is that the case or is there something else I'm missing?

[DewCatTea-Bob]

" I've been told that the slash mark is for 450s only.
Is that the case or is there something else I'm missing? "

____ First, I'm thinking that I've seen the slash on some of those gears even before the 450 was produced, (my memory is not clear on that though).
If that slash is on the retarded side of the dot, then that's a plausible notion, since the 450's ign.timing is about 5-degrees less advanced.
However, resetting that alignment just one tooth, moves the ign.timing a full 24-degrees ! So that far exceeds the relatively small difference in timing between the 350 & 450 ! _ And thus doesn't seem to fit the notion that the 450 must use a separate timing-alignment !
__ There must be another cause for your (coincidental) outcome however, because the slots in the points-plate ought to allow proper setting of the ign.timing regardless of which timing-mark you've chosen, since those adjustment-slots should provide about the same amount of radial-adjustment.
So don't worry about which mark you picked to align with, unless the plate's adjustment-slots do not allow you to set your static-timing between 10 to 5 degrees BTDC (with a points-gap of .015" +/- .003") !
__ So you see, the actual ign.timing is what's really important,, and the actual gear-alignment to achieve it, is of no real concern !


DUCATIly,
DCT-Bob

[frankfast]

That is the case. When the dots were aligned the points plate was rotated to the end of the slot and I believe that I couldn't retard the timing enough. The kickstarter would kick back a lot indicating it was too advanced. By aligning the slash with the dot I was able to achieve static timing at 7 and the points plate was able to be advanced and retarded an equal amount. It makes sense although someone else read in a 350 manual that the slash was for 450s only and indicated that there must be something else wrong. The bike runs and starts so I'm not sure he is correct.

[DewCatTea-Bob]

" When the dots were aligned the points plate was rotated to the end of the slot and I believe that I couldn't retard the timing enough.
By aligning the slash with the dot I was able to achieve static timing at 7 and the points plate was able to be advanced and retarded an equal amount. "

____ This leads me to wonder if any of your related parts are not original to your 350!?
(As I believe that the more advanced 'dot' location is intended for 250 models which employ the 18-degree advancer-unit and have a 22-degree BTDC static-timing.)
Otherwise, it seems certain that the timing-dot on the male-tooth of the crankshaft is one tooth retarded from it's intended alignment with the female-dot location on the oil-pump gear.
__ Hopefully, Eldert will have a point to make on this issue !


Curious-Cheers,
-Bob