Manual ignition

[townsends20]

Hi all.
               Still on the road with my rgs and loving it, but after 40 years it's not the same as it was. (ma-by it's me)
Anyway I need some input riding with manual ignition as I have always been on automatic in the past. First: have I set it right? With 10.5 to1 pistons & a 375 cam, I set it fully retarded that is with the lever closed with the cable slack  at 3/8th BTC. It starts well and runs well. (still running in so taking it slow for a bit.) I need to know the best way to run it without doing any damage, I adjust the lever as I go just to take it out of the pinging zone! Is that right or is it just trial and error . Also best s/plugs to use.
              Steve.

[bsa-bill]

Far as I know Steve ignition is set at full advance for all models, this being the position it runs at.
Retard position is for starting otherwise you get it kicking back (also retard helps on hills and limits pinking)
I don't have a RGS and never have had a manual A/R, from what you say though I would have thought cable slack was advanced

[Triton Thrasher]

Engine is timed at full advance.  Full advance is the lever position for normal running.  Any retarding is for starting and maybe idling or walking-speed travel.

If it's pinking, change to a lower gear, assuming you know the mixture is not weak.

[cotterpinkid]

Hi Steve,

Is not cable slack = fully advanced - this is correct for setting ignition timing (it's just knowing your advance from your retard).

Brian

[a10 gf]

On mine it's this:
Full advance = camring position fully ccw, control cable (lh side of cam housing) adjusted to have some minute amount of slack.
Max retard = camring fully cw. Timing to be set with ring full ccw.

[townsends20]

Hi  I am still confused,
       I am a fag paper and pencil guy, and its always worked for me. You tell me if I have got it wrong.. With the pistons at 3/8in BTDC  the cable in slack with the points just releasing the fag paper or do I have to have the cable fully tight. (plane English please as I have been in hibernation for the last 35 years)
  Steve.

[cotterpinkid]

Steve,

That sounds spot on to me  wink2

A little bit of slack in the cable ensures that the cam ring is in the fully ADVANCED position i.e. it is against the physical stop within the magneto and is not reliant on cable adjustment (in your original post you refer to this as being retarded, but it's actually ADVANCING the ignition - it's firing earlier when advanced). You should think of it in the way that you are advancing the spark (firing earlier) rather than advancing the the piston position in relation to the spark.

I've just been through an ignition timing performance with my GF. I set the timing to 30 degrees BTDC and when I strobed it the other cyclinder was firing at 25 degress (retarded in comparison). The fault lay with a badly machined repro cam ring which I've subsequently binned.

Hope this helps

Brian

[a10 gf]

Steve, to dispel any confusion: remove the mag points cover and watch the cam ring movement when actuating the lever.

camring max counter clockwise = advanced & normal running (and timing set position).
max clockwise = retard & position for starting engine (very small chance of kickback) + idling.

[BSA_54A10]

And remember that the advance / retard can be on either side of the maggy, so as suggested, take the points cover off.
Rotate the engine to make sure that you have the direction of rotation correct.
Now work the advance / retard lever.
When the cam ring moves in the opposite direction to the rotation of the points it is advancing the timing
The opposite is also true.
So some levers will pull to advance while others will pull to retard.
You should always check.