Hi Beags,
The FRCs (RAF) say use left (impulse) as does the BAe manual. But I have been told by a Lycoming chap to use both. I cannot think what the disadvantages are for using both; if we get a good spark from the impulse mag, then surely the No 2 will have no effect, good or bad.
Mind you, my engine turns very slowly as I need a new starter motor. I'm going for the lightweight SkyTec which has good reviews. That said, it can overheat if used for too long.
Now, having read Cockney Steve's explanation, I think I'll try starting with just the impulse mag, though I have not had an examples of kick-back using both.
Last edited by sharpend; 17th Aug 2013 at 11:53.