Author Topic: Manual advance  (Read 354 times)

Online RoyC

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Manual advance
« on: 10.04. 2018 14:12 »
I have a manual advance / retard mag on my shooting star.
Is the fully advanced position cable pulled tight or fully loose ?
I have assumed it is fully tight for normal riding, but,  *dunno*
My bike is a 1958 A7SS
Stafford UK

Offline cotterpinkid

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Re: Manual advance
« Reply #1 on: 10.04. 2018 16:03 »
...is it not the other way round?

When looking at the points end of the magneto, slackening the cable allows the cam ring to move in an anti-clockwise direction, thus 'Advancing' when the spark is released, in relation to the position of the piston in stroke, and allowing full combustion of the gases. Pulling the cable tight will move the cam ring clockwise (when looking at the points end), thus firing later i.e. retarding when ignition occurs (firing later in the stroke). Magneto rotation direction is given when looking at the drive end of the magneto - counter clockwise for us.

Wait for other responses....
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Online Triton Thrasher

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Re: Manual advance
« Reply #2 on: 10.04. 2018 16:42 »
Turning the cam ring in the opposite direction against the rotating points advances the timing.

Usually slack cable for full advance, but not always.

Online Billybream

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Re: Manual advance
« Reply #3 on: 10.04. 2018 16:53 »
Slack cable on mine is fully advanced.
Always slightly retard for starting, prevents kick back and painful ankle
1960 Super Rocket, owned since 1966, back on the road 2012 after being laid up for 29yrs.

Offline a10gf

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Re: Manual advance
« Reply #4 on: 10.04. 2018 17:14 »
With cable entrance on left side of magneto:

retarded with 'tight' cable (= cam fully clockwise)
advanced (normal riding and timing set) with cable 'loose' (= cam fully anticlockwise)

If cable entrance on right side (does that exist?) the above is reversed.

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Online RoyC

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Re: Manual advance
« Reply #5 on: 10.04. 2018 18:14 »
Thank you all for the response.
As I got the choke lever all to cock, I thought that I would check to see if I was doing the advance correctly.
I do give it half way retard for starting, I was not quite sure about after it started.
My bike is a 1958 A7SS
Stafford UK

Offline a10gf

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Re: Manual advance
« Reply #6 on: 10.04. 2018 18:57 »
With timing correctly set, setting retard position should stabilize idle rpm, making it smooth and even, sign that things work correctly :O)

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Online RoyC

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Re: Manual advance
« Reply #7 on: 11.04. 2018 14:10 »
With timing correctly set, setting retard position should stabilize idle rpm, making it smooth and even, sign that things work correctly :O)
This was another reason why I asked the question as it ran smoother (stationary) with the cable pulled tight.
My bike is a 1958 A7SS
Stafford UK