A homemade igniter bracket for a Bates & Edmonds Bull Dog
A Bull Dog Gets Its Spark Back
Peter Rooke's nearly restored 1-1/2 HP Bates & Edmonds Bull Dog.
Editor’s note: This two-part article is a supplement to Peter’s four-part series on restoring a 1-1/2 HP Bates & Edmonds Bull Dog, which began in the October/November 2008 issue of Gas Engine Magazine.
I had identified at an early stage of my Bates & Edmonds Bull Dog restoration that the engine was originally supplied with a Webster oscillating magneto, and had therefore been on the look out for one for well over a year.
I needed an M type magneto for this small engine and had failed to win a number of them I had bid for on eBay. Eventually, I was successful, though the Webster I found was an AMM – not the exact model I needed (having the more common clockwise rotation when tripped). But it appeared to be in good condition and was described as hot.
I understood that it was an “easy” matter to convert the magneto’s rotation for the Bull Dog so I then started to advertise for the appropriate igniter bracket, with the reference number 303M50. I was not in the least surprised that I failed to get any response and so, rising to the challenge, I decided to make one.
I had two options: make a pattern to get a casting made or try and fabricate one. I still had a small part of the old bracket and I scaled a number of photographs that I had of the correct bracket for the dimensions. Thinking that I might not get all my estimated measurements completely right, which would have forced me to alter components when assembling it, I decided to fabricate the mounting. In addition, I had a small part of the original bracket that had been used as a blanking plate on the engine, and I could make use of this, thus preserving another small part of the original engine.
The next step was to think about the order of work. I could see that care would have to be taken to ensure the trip lever of the Webster was aligned properly so that it would be activated by the trip arm and would then hit the movable electrode. I therefore planned to make the valve rod clamp and trip arm fittings first, so that I could then clearly identify the width measurements. I then built up the main body of the igniter and the electrodes, and then made the platform on which to mount the magneto.
While some dimensions could be accurately accessed from current parts, there was some estimation of others by scaling numerous photographs, the shape of some parts being set out in the line drawing in the Bates & Edmonds instruction leaflet I had purchased.
Valve rod clamp and trip arm
The first part to be made was the valve rod clamp of the trip mechanism, which fits on the end of the push rod and is also bolted to the exhaust pivot arm.
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