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MG Midget and Sprite Technical - Fuel pump polarity

Are SU fuel pumps sensitive to polarity?
I need to source a pump for my Sprite which is positive earthed. I wouldn't want to buy one that only served to drain the carbs!

MGB pumps used to be polarity sensitive, but not Spridgets, I believe.

The pump canít actually run backwards, as the armature just moves linearly and there are two valves in the pump body.

The polarity is only to do with the electronic components used, if any.
Dave O'Neill 2

Some info from Paul Huntís MGB site.

AFAIK Spridget pumps never used the diode-resistor.

This only applies to Ďpointsí pumps. Electronic versions are polarity sensitive.
Dave O'Neill 2

Hi Guy

I use a Facet silver top in my frog mounted on the o/s wheel arch where the midget one goes. Its mounted on insulated rubber 'cotton reels' so it polarity does matter. (I am still positive earth) I think the Facet's are more reliable than the SU ones. Mine was purchased in 1983, has never missed a beat and is still going strong!
Bob Beaumont

Thanks all.
The polarity question was a genuine issue, but the idea of it drawing fuel out of the carbs was just ment as a joke!

Whoops missed the 'not' after the word does!
Bob Beaumont

This thread was discussed on 13/09/2019

MG Midget and Sprite Technical index

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