> As a newcomer, I am still confused but overall, I have been getting
> more positive feedback vs. negative feedback. Plus, I asked for
> objective observations and actual experience with the 912S. I think
> Terry is simply stating his experiences. Hopefully we'll all learn how
> to get the engine to run smoother than he is experiencing.
>
> Does anyone out there have any suggestions or solutions to the rough
> start/stop and idle of the 912 S?
My twopennyworth, although with the problems I have had I can't claim to be
an expert.
The idle should be 1600 - 1800 when the engine is hot. Do not let it idle at
1400 as it will be rough.
Start/stop :
Start, use the Heavy Duty starter. It whizzes round the engine so much (50%
100% ?) faster than the standard starter and it catches straightaway so no
bouncing on start.
Stop, Ease off the throttle down to 2000, turn off one mag, ease throttle to
idle (maybe 1500 with only one mag) and immediately turn it off. Much
smoother I find.
Remember that smoothness is almost always associated with the adjustment of
the carb balance and that means having carefully aligned throttle cables
(inner and outer). I have added an extra return spring on one carb to
counteract the apparent inconsistency in the linkages. (A re-installation
---From scratch is planned). Also as you spend almost all the time at around
5000 rpm it is the 5000 carb balance that must be adjusted, not any idle
figure. If it doesn't seem to balance properly then you are getting
inconsistent positioning of the throttle levers due to imbalances in the
cable inners and outers.
As the carb balance can only be set at one rpm it must be 5000 even if the
idle balance is then out.
With mine there is a vibration at 3000 rpm. If it is bad it means the 5000
balance is out. When the 5000 balance is OK then the 3000 balance is
_almost_ OK ! Either way avoid the use of 3000 !
HTH, and I am happy to be shot down in flames. Don't forget that if you are
getting propeller "kick-back" at start you are knackering your sprag-clutch
and left too long the sprag clutch will have to be replaced, It is a much
more difficult/expensive job than just changing the starter.
Richard
Richard F.W. Holder 01279 842804 (POTS)
Bell House, Bell Lane, 01279 842942 (fax)
Widford, Ware, Herts, 07860 367423 (mobile)
SG12 8SH email : richard.holder@avnet.co.uk
++++++++ Please note new email address ++++++++
Europa Classic Tri-gear : G-OWWW, 912S Airmaster, High Cross
PA-28-181 : Piper Archer : G-JANA, EGSG (Stapleford)
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