22-07-2024, 09:09 PM
Hi
It looks unusual to me, the toggles seem to have slots instead of holes, I can only think someone has modified them but what they were trying to achieve is a mystery. I believe the reason toggles have two holes is just manufacturing convenience, so that the same part suits clockwise or anticlockwise variants. Only the inner holes are used for the springs.
The amount of elongation of the springs is tiny, especially when there is only a small amount of advance coming off idle. This makes the design very susceptible to any wear. A sign of this is weights that do not close together at rest, or can be pried apart very easily. The static timing is then somewhat random ! Sometimes fitting slightly shorter springs (fractions of a millimetre) can compensate for wear.
The attached photos at rest and maximum advance are of my own DK4A which I recently overhauled. The standard springs are identical and give a more or less straight line of advance with a maximum of 8 distributor degrees (16 crank degrees). The limit is set by the movement of a peg within a circular hole in the action plate which I measured as 21/64 inch diameter (8.3 mm). Any wear/ovality in this hole increases the maximum advance.
It looks unusual to me, the toggles seem to have slots instead of holes, I can only think someone has modified them but what they were trying to achieve is a mystery. I believe the reason toggles have two holes is just manufacturing convenience, so that the same part suits clockwise or anticlockwise variants. Only the inner holes are used for the springs.
The amount of elongation of the springs is tiny, especially when there is only a small amount of advance coming off idle. This makes the design very susceptible to any wear. A sign of this is weights that do not close together at rest, or can be pried apart very easily. The static timing is then somewhat random ! Sometimes fitting slightly shorter springs (fractions of a millimetre) can compensate for wear.
The attached photos at rest and maximum advance are of my own DK4A which I recently overhauled. The standard springs are identical and give a more or less straight line of advance with a maximum of 8 distributor degrees (16 crank degrees). The limit is set by the movement of a peg within a circular hole in the action plate which I measured as 21/64 inch diameter (8.3 mm). Any wear/ovality in this hole increases the maximum advance.