Trevor, I learned the hard way that having a separate starter cranking button
can
be very useful. My present engine's an 'S' with high compression and I agree
totally with what the other respondents have stated. My original engine was
a 912UL and never gave starting difficulties, having the same/similar
compression
to the 914.
However if you opt for a heavier propeller such as the Airmaster and some day
find
that your battery has low charge, then "kick-back" is a possibility because
the propeller inertia needs to be overcome before giving the engine sparks.
First press the separate starter button for 1 or 2 seconds before either
flicking
the "mag" switches to ON or turning the ACS key to BOTH.
This technique is used by many/most pilots who have the 100hp 'S' engines with
heavy propellers, or so I'm told. The "hard way" mentioned above involved having
to replace the sprag clutch after repeated "kick-backs". A separate starter
cranking button is a simple and cheap option.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=481621#481621
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