Paul Hammarstedt wrote:
> FWIW, I have had spark plugs make spark when taken out but fail to spark when
> installed. They were brand new Champions that experienced flooding on the
> attempt to start the engine.
> An unusual failure perhaps, but thought I'd throw it in.
> Sorry if plugs were already addressed, I deleted most of this thread and can't
> remember previous steps taken.
Back in the old recip helicopter days, the A&P guys showed me that very thing.
had some sort of tester that put air pressure on the plugs (much like
the cylinders) and tested them that way. They sure can fire on the bench but
under pressure. I think it would be unlikely that you have 4 of them that will
work but, as Paul suggested, it's worth a look.
Lone Jack, MO