distributor query

[bootlid]

on my 1950 mm lowlight,it was noticed that the distributor moves about quite a bit causing alteration to the setting of the points gap,however does not cause running problems except baddly pitted points,at present the distributor is secured by one small bolt which also secures throttle cable bracket,,on the distributor housing(painted green)there is a small hole which may have held a cotter pin which is missing,anybody any ideas or have a spare pin.[frame][/frame][frame][/frame]

[bmcecosse]

Moving about is hopeless - fix it down somehow! Maybe mount the throttle cable elsewhere?

[bootlid]

could you be more specific please on remedy, i,m not a mechanic although capable of some work on the minor,thanks.

[mike.perry]

You have the later USHM3 engine. The distributor should be clamped in position by a cotter through the hole. This is a bar the same diameter as the hole with a thread and nut on one end. The bar is machined so that it is cut away to the same shape as the distributor hole.
I had a new cotter made in a local machine shop. The bolt on the original cotter is 1/2 AF, maybe 1/4 Whit but for extra strength I had my cotter produced with a 9/16 AF nut with a corresponding increase in the thread size.
There should not be any other form of distributor clamp with this engine. The earlier USHM2 engine has a clamp around the distributor which is secured by a bolt into the cylinder head. This earlier system has the advantage that the distributor can be removed and replaced without disturbing the ignition timing.
The DKYH4A distributor is prone to wear in the shaft bushes, causing the cam and rotor arm to wobble and causing wear on the distributor cap contacts and an inability to set the timing correctly. There can also be wear on the prongs of the distributor drive dog which can be replaced, and wear in the jack shaft. The slots can be welded up and refiled so that the drive dog is a tight fit in the jack shaft.

[bootlid]

Thank you mike i,ll photograph your message and pass it on to a friend who may be able to help,by the way on removing the stud nearest to the throttle cable the distributor comes out easily and slots back in without upsetting the timing.