912iS

anyone installing a 912iS on a SS like to know how it is going
the electrical in the Rotax manual seems complex.

David K
SS Kit on order

Hi david,

I have just bought the engine and am doing our electrical diagrams now ( with assistance from an experienced person). Will let you know how we go and will be interested in sharing experiences on this one.

cheers

I have a 912is in my SS7 super sport. At 84 hours I upgraded it to the
912iS Sport (new intake manifolds and air box + new ignition coils). The A/C and engine now have 92 hours. The machine is a joy to start at any
temperature and with the sport upgrade has excellent power for short
field T/O and climb.

While the electrical wiring diagrams may look confusing at first they are not
complicated. The big issue which is quite different from most GA aircraft is
the use of a start power switch. I located the switch just to the left and slightly below the throttle. The lane switches, master switch and starter
switch are located on the left lower portion of the panel, quite similar to
most A/C. So to start; its right hand on throttle with throttle adjusted for
outside temperature, right thumb under start power switch, left index finger on starter switch and away you go.

I am using the Advanced 5600 EFIS which is programmed to accept the Rotax CAN buss so all engine instruments are present. Some might say
"well what about a EFIS failure in flight". To me the only critical thing is
WHAT IS THE ENGINE RPM? The rotax engine is very sensitive to over
speed and at the higher RMP's is difficult to determine by ear. So I added an optical prop Rpm sensor to cure that issue.

All in all I am quite pleased with the system and aircraft.

I almost forgot. My firewall forward kit came with a AERO VOLTZ 12 cell
battery. Because of the" before starting" load of master solenoid, EFIS, fuel pump, and engine computer I found that the capacity of the 12 cell was marginal. So I purchased the 16 cell and all is well. I use the 12 cell as a
additional engine backup power with it mounted behind the pilot seat. Because the type battery is very sensitive to being drawn below nine volts
(destroys the battery) I added to the before start check list : check battery volts prior to start. I would not attempt a start if the battery was below 11.5 volts. The 12 cell is not connected directly in parallel with the main 16
cell battery. I changed the backup power switch to a double pole,, double throw, NO CENTER OFF switch. Also the backup power circuit breaker is a toggle switch type. By proper operation of the circuit breaker and due to the wiring, I can keep the 12 cell isolated or put it in parallel with the 16 cell for charging or use, or direct it to the backup power switch.

for information, here is the start portion of my checklist

Thanks for posting your checklist Neville. I took this photo of the 'panel' the Rotax Dealer here in OZ uses to test the 912is sport engines. I thought it may be of interest to see to panel side of the wiring. (not suggesting we all use plastic boxes for the panel!)

cheers

r

here are some panel wiring, Taken before final dressing of harnesses.