Rotax 912iS fuel system tests

[neville]

I made first start on my 912iS (with Advanced 5600 for engine monitoring)
with instant start up but had a warning for lane B functions and some
data missing on 5600. After correcting a wiring problem with the data
buss all was well. The EAA recommended fuel tests require modification
as engine running is tied directly to the two parallel fuel pumps. Proving
adequate fuel flow at the injector rail input means little as one pump
puts out over 500% of the required full power flow. My system is plumed
as per the Rotax install manual starting with the #16 mesh finger strainers
at fuel tank outlets, through header tank, fuel valve, and to a 117micron
gascolator (the lowest point in fuel system), and on to the dual fuel pumps
which bypass adequate fuel flow when off. Then out of fuel pumps to a
mandatory 10 micron filter and on to the fuel rail input. The fuel rail pressure regulator returns unused fuel to the header tank.

So I related fuel flow tests to the output of the gascolator with gravity
feed for quantity and to the low fuel warning light for "out of fuel" tests.
Results were satisfactory. In pitch up test the amount of fuel required to
have gravity flow at was the tank level indicated as "no takeoff" on the
factory fuel placards. Have not done pitch down test yet.

Got lots of support from the McBeans for the 912iS fire wall forward
kit installation. Thanks. Richard

[DesertFox4]

Richard, thanks for the write up on the 912iS fuel system install . Very interesting to compare to the other Rotax engine fuel systems.
I did get an opportunity to see the new 912iS install first hand on Kitfox Aircraft's factory demo. plane while at the factory fly in. John and crew did a beautiful job on the install. Very precise and tidy.
I did not get the chance to fly behind the fuel injected engine however it sure started quickly and sounded very nice and ran very smooth.
I look forward to your impressions in flight with the engine. I hope it gives years of good service and saves you barrels of that expensive fuel.