Rotor arm play??

Just a quick one.

How much side to side play should the arm have when located on the distributor?

Cheers

Not a lot.

I know usually its very minimal and was expecting that to be the answer for these motors too. However I have quite a bit. Hoping its due to worn arm and not distributor. Will have to go get a new arm tomorrow to see if it fixes it or proves I need a dizzy.

If the rotor arm itself is loose on the distributor shaft, then either it is cracked, or the little flat steel spring inside it is lost or broken. Get a new rotor arm quick.

If the distributor SHAFT is wobbling about, it's time to think about a new distributor.

When that shaft runs off true, the ignition timing and dwell angle are both going to go wrong.

Worth fixing.

CharlesY

Its play in the arm... I took the arm off when I changed the vac advance unit and looked in the bottom of the arm. There was just the little square plastic notch to locate into the dizzy. No spring??

BigErn said:

Its play in the arm... I took the arm off when I changed the vac advance unit and looked in the bottom of the arm. There was just the little square plastic notch to locate into the dizzy. No spring??

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If the rotor fits snug to the top of the shaft it will be fine.

It's a matter of judgement now, how much free play is acceptable in the shaft.

If it is electronic ignition it won't matter so much as it will if it uses a breaker-point set.

CharlesY

there is a little bit of play usuallu (few mm sideways at the TIP of the rotor arm) but also there should be about 20mm worth of spring tension movement

one time my advance springs stretched so the arm was moving about.

if you remove the base plate (that which the vac advance unit is hooked onto) and look down into the bottom you will see the machanical advance unit - its pretty simple to get to tbh - visually inspect and see whats what.

a good dizzy will only have minimal play and very nice smooth but firm spring tension.

cheers