[AT] cold Farmall

[john hall]

Ralph, there is some truth to that. Our Allen magneto tester changes the 
RPM's by means of a variable speed. Also the "gap" for measuring spark 
strength is adjustable so you can tell  exactly how strong the spark is. 
While a mag is on impulse the spark is the same since the mag is turning the 
same speed whenever the impulse trips, regardless of engine RPM's. On some 
mags if the impulse locks out at a lower RPM than what the mag spins when 
the impulse trips, the spark will get weaker. However this is usually a 
speed lower than what the engine will run so it is no big deal. Once you get 
up to about 1/3-1/2 throttle you don't see any increase in spark strength. 
I've observed this  a few times when testing magnetos. This may be in part 
due to worn parts in the impulse. I've yet to see one that acts this way 
cause any trouble on a engine.

John Hall

>
> I remember being told years ago that if you cranked a magneto engine too
> fast you actually got a weaker spark as you would over-ride the impulse. 
> The
> only mag I have to deal with now is on the old Wisconsin one cyllinder 
> grain
> auger engine. And of course the pull start DC4, but thats another story.
>>
> Ralph in Sask.
>
>