Thanks Bud,
This is amazingly detailed information and exactly what I wanted to know
=93
thanks again.
You mention "I=99m not a huge fan of the 914 either as it has issues=9D
Would you suggest I bear in mind any upgrades in particular once I have don
e
the first start of the 914 ?
Bob Borger mentioned considering the high-tourque starter, so will bear thi
s
in mind.
I am planning to use the newer Lithium Iron aviation batteries which should
have more power and lighter, any thoughts on that ?
All help appreciated =93 many thanks
Regards
Trevor
From: <owner-europa-list-server@matronics.com> on behalf of Bud Yerly
<budyerly@msn.com>
Date: Sunday, 15 July 2018 at 1:48 PM
Subject: RE: Europa-List: Home made soft start module for Rotax 914
Trevor and to All:
Kickback of the Rotax was primarily the 912S. The 912 80 HP and 914 were
normally immune from this.
Rotax screwed the pooch on the 912S a bit.
The high compression taxed the old starter, and ignition timing was a bit
too advanced for the compression and the slow starter rotation during
initial start. Bob Berube had one of the early 2000 time frame 912S engine
s
and it would rather run backwards on start than forward even with a light
prop. Initially these early 912S engines even had the issue with the Princ
e
P tip which is a very low inertia prop.
Prop inertia was not the problem, the starter just couldn=99t hack it. It
barely got a 912S up to 200 RPM with a 12 volt battery. The planes with
slipper clutches also had a unique issue when the prop spun initially and
hit the first compression stroke, the slipper clutch would snap the prop
back and forth during the initial start.
That extra snap was hard on the sprag clutch but not as hard as a reverse
start when the ignition sparked and caused the detonation prior to TDC and
the engine would immediately stop if you were lucky or if one other cylinde
r
fired at just the right time, backwards she=99d go possibly running in
reverse. If you study the ignition system you can see one of the modules i
s
slightly more advanced than the other so killing the higher advanced
ignition on start reduced kickback or reverse start.
Todays 912S is a much better engine. Starting in about 2006 significant
912S changes were started. A better crankcase, a higher torque starter
which spins faster, and a properly adjusted sprag clutch, and a slightly
improved cam shaft means no start issues any longer, smoother running and a
higher TBO.
To live with the older engines, folks learned to have a well charged batter
y
to help the starter.
So keep the starter serviced. Keep the brushes and commutator clean of
grease and dust.
(Consider the high torque starter. A non Rotax Sky-tec starter is $400 .
Not too bad.)
Many purchased a soft start module which cut back the ignition timing durin
g
the first six or so seconds of start on the old 4 pin ignition modules.
(Today Rotax wants to sell you a whole new ignition module set (six pins an
d
a yellow tag is the new one which has the soft start built in.))
Others just started on one ignition if they installed separate ignition
switches.
Others opened the throttle to get the engine to spin faster, then turned on
the ignition, but that meant a separate start and ignition switch. Then
they had to pull the throttle back and choke at the same time while
crankingIt took 4 hands.
The Rotax factory never admitted they had a problem with the 912S. But the
y
have made significant improvements since 2008.
Props:
Rotax admits that if the prop inertia is below 6K it cannot damage the spra
g
clutch. No reputable manufacturer produces a prop for a Rotax over the
limit. Of course there are those that put too large a prop on the Rotax
then blame the prop. You can=99t fix stupid.
Warning:
If you have kickback on your old 912S engine or new engine, fix it NOW.
Check your starter, battery, and ignition modules and invest in the
electrical gear to fix it. Expect it to cost a pretty penny, but it is
worth it.
I=99m afraid I am not a fan of the older 912S and avoided them when I could
for years. After 2008 I found the newer 912S engines seemed to be fairly
free of kickback, and I have installed a couple since 2010 and those client
s
with the newer engines are pretty much trouble free mechanically. Of cours
e
I=99m not a huge fan of the 914 either as it has issues but frankly I still
prefer it over the 912S. But then again I have a love hate relationship
with every engine in an airplane. I=99m not prejudice, I hate them all.
Best Regards,
Bud Yerly
Sent from Mail <https://go.microsoft.com/fwlink/?LinkId=550986> for Window
s
10
From: owner-europa-list-server@matronics.com
<owner-europa-list-server@matronics.com> on behalf of William Daniell
<wdaniell.longport@gmail.com>
Sent: Friday, July 13, 2018 8:35:59 AM
Subject: Re: Europa-List: Home made soft start module for Rotax 914
=8BI agree with Bob=8B for what its worth.
the 914 has the same compression ration as the 912. I hav e a 912 turbo an
d
Ive never had a problem with kick back.
Will
William Daniell
LONGPORT
+57 310 295 0744
On Wed, Jul 11, 2018 at 4:10 PM, Robert Borger <rlborger@mac.com> wrote:
>
> Trevor,
>
> FWIW, YMMV. I have been flying behind a 914 that is about 15 years old n
ow.
> The only change I have made to my 914 regarding starting was to install t
he
> newer, high-torque starter. My engine starts quickly and easily. I see
no
> need for any soft-start module, ignition retarding software or any other
such
> stuff. I suggest you finish your kit following the factory instructions
and
> evaluate how the engine start goes before you get into any changes to the
914.
>
> Blue skies & tailwinds,
> Bob Borger
> Europa XS Tri, Rotax 914, Airmaster C/S Prop (130 hrs).
> Little Toot Sport Biplane, Lycoming Thunderbolt AEIO-320 EXP, Hercules Pr
op.
> 3705 Lynchburg Dr.
> Corinth, TX 76208-5331
> Cel: 817-992-1117
> rlborger@mac.com
>
>
> On Jul 11, 2018, at 2:55 PM, trevord <trevord@orcon.net.nz> wrote:
>
>
> Hello all,
>
> My first posting on Matronics.
>
> I have purchased a Europa kit which was started 19 years ago of wonderful
> quality workmanship but has an un-started, still inhibited 19 year old Ro
tax
> 914 engine. From my research, it would seem the soft-start option is crit
ical
> to the sprag clutch lasting for any length of time. I have read about the
> Bullyhawk modules, but they are no longer available and new Rotax ignitio
n
> modules are expensive.
>
> I read on the Rotax forum about a circuit that was home made that retarde
d the
> ignition on start-up by a user called Turbo-Tom but I cannot find enough
> information to work out how to replicate this and Turbo-Tom seems to have
> moved-on.
>
> Do any folks out there know of a reliable home-made solution to the defec
t
> that was built-in to the original Rotax engines in the form of inadequate
time
> before the timing switched to fully advanced, which is known to destroy t
he
> clutch in short order.
>
> My local Rotax importer of course suggests I buy a new engine.
>
> Regards
> Trevor
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