Ruston PT Impulse mag timing

Hi guys,  can anyone give me  some advice on  refitting the impulse mag to a PT as there is no marks on any of the gears and it must be 35 yrs since I last had an impulse mag on an engine,  also can you tell me  who is the most reasonable priced mag repairer these days.  Thanks Bill

Click on the link below and scroll half way down the page mate might help you out

http://www.stationaryengineforum.net/t6961p15-ruston-and-hornsby-pt

Thanks for the quick reply Abes but there is no marks on any of the geqrs and it is a
Wico A with an impulse drive. How do you time a mag with an impulse drive, is it the
same procedure as a chain or gear drive? Bill

Bill most impulse mags 'trip' when the crank is at TDC which on a PT will be when the flywheel keyway is at the 6 o clock position.  Just a matter of trial and error, keep rotating the mag gear until it trips on or slightly before TDC.

Pete.

Found this on another post should help

"If your impulse clicks at the timing mark then your timing is wrong.

The impulse does two things:
1. It uses the spring to make the mag spin quickly through the spark; hence larger spark.
2. It retards the timing to (roughly) TDC to aid starting.

Your impulse should click around TDC, so that when the engine accelerates beyond the impulse the spark retards to the timing mark.

If you turn the engine BACKWARDS until the points just close, your timing mark should be at the top. Now when you turn the engine forwards the impulse should click near to TDC."