Bamford EG3 backfire when trying to crank it up.

Can anyone give me advice on the following for a Bamford EG3 that backfires badly when I try to start it :- When should the "impulse" occur on the Lucas Magneto, is it at Top Dead Centre or how many degrees before or after TDC ?
What is points gap when points fully open ? Sparkplug gap and recommended plug ? Anything else I should be thinking about before it finally "eats" me would be much appreciated.

Assuming its the same size as my lister D the points should open about 2" before top dead centre, I would give the points a 13 thou gap.

Maryalice

I am sure the correct way to set the impulse is by setting it in reverse, thats how I did it many years ago on my EV4, I'll try and find the procedure.

This may sound bizarre but I had an EV2 that had a vicious backfire on starting unless the spark plug was very clean. I had to wire brush it every time even if there was no carbon etc, I never worked out why. Once clean it would start easily and run all day

I didn't think that the Lucas mags on the Bamford EG series actually had an impulse fitted, the Wico ones certainly did though?

Pete.

Pete.

Here is the page out the manual, can you find the SPARK-R on the flywheel, mine were in a terrible condition and I think I found it, I also remember I had 2 lengths of masking tape working out what was happening where,
Untitled by chrismac2012, on Flickr

Good luck