: Nice thought though. We've already done all the easy and normal stuff....
:
: -Cory
:
: The plugs will fire during the runup, one mag at a time, but
: during flight when both mags are firing, there may be one or two that
: don't. Engines that have both mags timed at the same point BTDC need
: to be set as accurately as possible so that both plugs fire at the
: same time or very close. If one fires well before the other, the
: cylinder pressures may rise to a point that the other plug, being a
: little weak, can't fire and now we get a bit of roughness and loss of
: power.
: There are a few engines that specify a significant difference
: in their mag timing. I don't know how they handle spark blowout with
: that setup. Some of them were pretty old models that used resistorless
: plugs; perhaps they didn't suffer the same way that plugs with
: resistors do.

Interesting thought. I'm still skeptical that could be it, though. I've timed the mags a few
different times over the course of the year or so it's occasionally happened. I'm pretty anal about
getting them dead-nuts on each other and exactly at 25 degrees. I don't want them advanced at all since
I run autogas, but don't want to detune them either.

Also, I've done the mag drop in flight when I suspected that it was happening. Everything was
fine... power smoothly decreased as expected. The "blow-out" thing could still be doing it, but I
wouldn't think it would only do it for the first 60 seconds of flight occasionally. It should be more
consistent or reproducable with higher MP (lower altitude takeoffs), etc.

-Cory


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************************************************** ***********************
* Cory Papenfuss, Ph.D., PPSEL-IA *
* Electrical Engineering *
* Virginia Polytechnic Institute and State University *
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