Best Ignition switch?

[TJay]

looking for a good ignition switch for my jabiru install, all the ones at aircraft spruce that are left right start say not recommended for electronic ignition? what are you rotax guys using?

[Dave S]

Hey TJay,

Don't know if this helps.....but, the switch that came with our kit for the 2008 vintage 912ULS was the OFF-L-R-START type - it also had a diode that was to be used on the starter solenoid. The L-R is a ground where OFF grounds both. Obviously the 912ULS Rotax is an electronic ignition - however, there are various types of "electronic ignition" and the specific type might come into play.

If the "not for electronic ignition" was general info from A.C., In addittion to info from this forum, I'd be inclined to check with Jabiru and see what they recommend on their engine installs.

Checked your photo album - Plane is looking good man!:)

[Av8r3400]

I used a keyed on-off switch from NAPA as a master, two 250 volt ac heavy duty toggles for ignitions and a push button for the starter. An on - off - start switch could have also been used, but I'm weird and wanted a push button.

I'm not an electrical engineer so I defer to those who are more knowledgeable (LEAF & Lockwood) when they say the left - right - both - start switches are problematic on these types of CDI ignitions. Brett from LEAF and Phil Lockwood himself have both told me that they have replaced many of these switches which had failed, often causing further ignition component damage.

[TJay]

so when you wire them up through the toggle switches does that mean someone can flip the mags on and swing the prop with out a key and have a running airplane?

[Av8r3400]

Theoretically, I guess that would be correct. Hand propping a 912 is possible, but not as easy as a Conti-lyco-saurus engine.

The ACS switch wouldn't be hard to defeat either.

[jtpitkin06]

There are lots of ways to wire in a safety circuit to prevent accidental starting, but you do so at the risk of adding a single point failure. Although hand propping a Rotax can be done, it takes some effort. (Do a search for You Tube Hand Prop Rotax. ) Youll need to get 220 engine RPM which is far above the casual moving the prop out of the way in a crowded hangar. Accidental starting of a Rotax by moving the prop is highly unlikely.

If you are worried about theft, two things carried in the standard airplane repo kit are wire cutters and jumper wires. Who needs keys? Snip the black yellow wires and jumper the starter. Zippity do dah.

With that in mind I'd go for the safety of flight wiring and just turn off the ignition at the end of the flight. Keep ignition systems simple with as few failure points as possible. Nix the hidden switch idea and spend your time making a good door latching and locking system.

[avidflyer]

When I installed the Jabiru engine in my Avid MK IV, I just used the switch that was already in the plane. Probably the one that Aircraft Spruce sells. If I didn't have that switch, I would just use a keyed switch to start the engine and 2 toggle switches for the mags like Larry did. I tried several times, and was never able to start my Jabiru engine by hand propping. It has to turn over at about 300RPM to make spark, and that takes a pretty hefty flip on the prop. At least I couldn't do it. JImChuk

[TJay]

Bringing this back up, So a while back I contacted Jabiru and they said the best switch to use is the ACS switch, http://www.aircraftspruce.com/catalog/elpages/igswitches.php?clickkey=226119 Which is great for me in two ways because I already have this switch, and I cannot for the life of me find an exact match to my tyco breaker style toggle switches for shutting off the mags, but since I bought it many years ago I have lost the diode that goes on the starter relay, Do any of you know what diode I need to buy, I may end up at radio shack today,

[Dave S]

TJ,

Might check this item on ACS to see if it matches your switch number.

http://www.aircraftspruce.com/catalog/elpages/solenoidassy.php

Looks like this diode assembly for the switch/solenoid is intended for a couple applications

[PapuaPilot]

This diode will work on any application that is uses a solenoid. When hooked up correctly the diode dissipates the collapsing field of the solenoid so it doesn't create a spark across the starter switch when you release it. Without the diode your starter switch can slowly burn up across the internal contacts and eventually fail.

This is called a clipping diode. I made my own using an IN4004 diode, heat shrink and crimped on the solderless terminals.

[TJay]

hey thanks guys