[AT] cold Farmall

[Jim & Lyn Evans]

What is more important when you are hand cranking is that the impulse 
retards the ignition to reduce the chance of kick back.  I can give my 
DC or CC a quarter turn (just barely rolling it over) and the impulse 
will deliver a good spark with little fear of kicking back.  You try 
spinning the crank and you will get hurt.    The first time I roll it 
over when I start a tractor I make sure the impulse trips.  If it 
doesn't, I fix that before going any further.

On 1/19/2012 8:07 PM, john hall wrote:
> 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.
>>
>>
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