BSA B33 Ignition timing

Started by Meyer, 20 April, 2024, 21:01:53

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Meyer

On my BSA B33 154, the advance/retard punger cable is on the right side of the magneto, when looking from the end of the magneto (contact breaker point of view) or from the left side of the motorcycle.

In the Haynes manual it is opposite, does that mean the the advance/retard lever on the handlebar should be slacked completely off when setting the timing of the contact breakers ?

neil1964

This one, immediately below, is the slack advance of later B33s and Gold Stars:

On this you set the timing BTDC with the wire slack

This one, below, is the tight advance type:

With this you set the timing fully advanced with the wire tight.

Jim S

The points rotate in a clockwise direction. Rotating the face cam counterclockwise makes the points plunger reach the high point on the cam sooner or more "advanced". So rotating the cam counterclockwise is always advancing the ignition regardless of what side the cable enters the magneto.

Jim

Meyer


V500

Quote from: Jim S on 21 April, 2024, 13:46:29
The points rotate in a clockwise direction. Rotating the face cam counterclockwise makes the points plunger reach the high point on the cam sooner or more "advanced". So rotating the cam counterclockwise is always advancing the ignition regardless of what side the cable enters the magneto.

Jim

Indeed, but the point is one side is slack wire advance and the other slack wire retard, so the handlebar lever works in the opposite direction.

Meyer

Thanks to all !
I got its startet yesterday, after it has been in a barn for 9 years :-)
-Meyer

fragged

thanks for this .. so the old adage for tightening bolts also applies here.

'Leftie Loosie - Righty Tighty '