I have run and maintained my 504 for some 18 years. The Ducellier M48 distributor has presented somewhat of a conundrum for many years.
Basically I have had difficulty getting the rotor arm to the correct position vis a vie the spark lead terminals in the distributor cap, at the point where high voltage current is released, as the contact points open.
Prior to modifications (i've tried several with varying degrees of success) the rotor arm has just passed the spark lead terminals in the distributor cap when the contact points open. The result is extra strain on the coil as the spark has greater distance to jump, vastly decreasing the lifespan of ignition coils.
I've tried several modifications.
1) Advanced the 3 bolt holes in the distributor body which determine the position of the contact set by 4mm. The disadvantage is the clips holding the distributor cap do not align neatly.
2) Currently I have advanced the tongue (abuts on the distributor cam) in the moving arm of the contact set by 5mm. This solution seems to be working quite well.
Has anyone else encountered this problem? I can only surmise that either the Valeo contact sets I have been using are incorrect for this distributor, or the inner rotor lug which fits into the slot at the top of the distributor shaft is incorrectly positioned?
Basically I have had difficulty getting the rotor arm to the correct position vis a vie the spark lead terminals in the distributor cap, at the point where high voltage current is released, as the contact points open.
Prior to modifications (i've tried several with varying degrees of success) the rotor arm has just passed the spark lead terminals in the distributor cap when the contact points open. The result is extra strain on the coil as the spark has greater distance to jump, vastly decreasing the lifespan of ignition coils.
I've tried several modifications.
1) Advanced the 3 bolt holes in the distributor body which determine the position of the contact set by 4mm. The disadvantage is the clips holding the distributor cap do not align neatly.
2) Currently I have advanced the tongue (abuts on the distributor cam) in the moving arm of the contact set by 5mm. This solution seems to be working quite well.
Has anyone else encountered this problem? I can only surmise that either the Valeo contact sets I have been using are incorrect for this distributor, or the inner rotor lug which fits into the slot at the top of the distributor shaft is incorrectly positioned?