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MG MGA - Dizzy questions

Does anyone have an exploded diagram of the 25D4 distributor, or a link to same? (Don't ask why!)
Also, I don't have the cam retaining screw. What size is it?
Art Pearse

OK, don't really need the diagram. Just need to know does the spacer washer go inside the body, under the rotating assembly, or outside, above the dog drive? I found the cam screw - is there suppoed to be a spring washer with it? Next time I will take better notes!
Art Pearse

Art. Took the measurements on the screw last evening, but have not had time to post until now. For the archives, the screw is, most probably, a 2BA since it fits into a 10-32 screw check plate. For all practical purposes, the two interchange. The diameter of the head is .375" and the length of the shaft is .325". The diameter of the distributor shaft is .316", so the head of the screw needs to be larger than this if a substitute is to be used.

Inside the body of the distributor, between the upper end of the bushing and the lower section of the distributor shaft, is a nylon washer/spacer. I have, frequently, found this piece to be missing and it does not seem to have a great effect on distributor functioning. I suspect it is to prevent wear on the upper end of the bushing.

At the bottom end, there is the distributor body, then a bronze flat washer/spacer, then the distributor drive dog. Be aware that the distributor drive dog and distributor shaft, to which it is secured by a drive in pin, are drilled slightly off center. Thus, they only go together, correctly, when the two holes are perfectly aligned. It is possible to drive the cross pin in part way when they are improperly aligned, but it will not go completely through in the correct manner.

Les Bengtson

Thanks Les. I too have the nylon washer. So the brass one goes above the drive dog. Thanks for the tip about the off-centre hole!.
Art Pearse

This thread was discussed between 11/11/2009 and 13/11/2009

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This thread is from the archive. The Live MG MGA BBS is active now.