ignition points not staying put

[grasshopper]

Hi all. I'm sorry if this is a silly question. I have an issue with my ignition points becoming loose. They are secured with two screws. As far as I know, there is no washer required under the screw. My points keep on loosening and loosing their gap. I've just installed two lock washers. I hope this will solve my problem. Has anyone had this problem before ?

[spider2081]

I am a firm believer in replacing hardware with new when replacing distributor parts. The threads in plates the screws go into are thin so only a few threads are there. After years of use the threads on the screws and the plates could be worn not allowing proper tightening. Replacing the screws should at least fix 1/2 of the issue.
I think its more common for the screws that hold the rotors to loosen. This allows the rotor to strike the cap and they both break killing the engine.

[kmead]

You can buy a new plate for the points to be screwed into. MWB has them. Given the issues you are having I woul look into getting the plate. Or finding a later model electronic distributor from a 79 or 80 with carb preferably.

Sometimes if your bearings in the distributor are worn the shaft can wander and your gap can "disappear".

Rotors on most late model Spiders are push on, no screws. Never had one with the screws come off on my 850 or my 1438 Sport Coupe which both use the Marelli with a two screw rotor.

[spider2081]

Rotors on most late model Spiders are push on, no screws.

Not sure what constitutes a late model Spider but my 81 Spider 2000's rotor is held in place by 2 screws with wave washers. I replaced the screws with new ones and the wave washers with internal star washers.

[seabeelt]

The screws need flat washers under them or at least between the lock washer and plate. This prevents the points from moving when you tighten the screws. Particularly the one nearest the actual points gap