Hand prop a 914????
Here's some text (cut and pasted) from the Europa XS Rotax 914 Installation
Manual, Issue 4, Page 1-1, September 2001:
"Caution: It should be noted that before the two ignition leads which come
---From the ignition box are
earthed, the ignition is "live". Even though the engine speed must be at
least 1200 rpm for the
ignition to fire, it would be a sensible precaution to fit the magneto
switches before further work is
carried out on the engine, or at least temporary earth leads connecting the
ignition wires to the
engine casing."
Did this "expert" suggest how to get 1200 RPM by hand propping?
Let's do some math. 1200 RPM at the engine is 494 RPM at the prop (the gear
ratio is 2.4286:1) so if you grab the prop at, oh let's say, 30 inches (76
cm) from the hub's center you must fling the thing at 88 MPH (141 KPH) or
129 feet/second (3934 cm/sec). Putting that in perspective, a Major League
baseball pitcher, or a really good amateur, can throw a baseball a bit
faster than that, but that is a whole lot easier than turning over a Rotax
with it's 9:1 compression ratio.
Best regards,
Rob Housman
A070
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com]On Behalf Of Ron Parigoris
Subject: Re: Europa-List: Night and Day 2
<rparigor@suffolk.lib.ny.us>
Hello DJA727
<snip>
> @@@@@@ First, I don't know what you mean by "redrive". Are you
referring
> to the gear box?
(XXXXX) Yes I what refer to as redrive is the gearbox. For whatever it
is worth, the 914 has a slight different ratio compared to 912 or 912S.
also he said you can hand prop a 912 or 914, but with the higher
compression of the 912S you can not hand prop.
<snip>
Ron Parigoris
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