Misfiring Massey 35

I recently converted my Massey electrics from a generator to an alternator. I used a Lucas and connected the Bat terminal directly to the stud on the battery lead. The field goes via a red diode to the ignition.

The old lady starts without a problem and as the revs go up the red light goes out. I assume the alternator is charging.

Problem is that a misfire has now appeared and the old girl only runs for a minute or two before suddenly cutting out.

I can't seem to locate the problem. With the ignition switched off, a test light connected between the bat terminal on the alternator and the negative post on the battery indicates some power. With the ignition switched on, it applies to the postive. The battery seems, a week after the conversion, to have run flat.

Please help!

Regards,

John

Thyge

No, it seems that my 35 (a gas version) has negative ground. I assume so, as the negative terminal of the battery has always been connected to the bodywork.