What’s your 912iS idle rpm set to?

Rotax Wizard wrote:

OK simply look at your throttle body at the bowden cable lever.  If you have a single adjustment screw this will have Loctite.  If you have a newer engine there may be 2.  Use the outer one to adjust and do not touch the inner.  The inner is adjusted by the throttle body producer to set it with matching the TPS on the other side of the shaft. The inner one has Loctite. 

i did attach a picture last time, but here is is again if you missed.  This is from a 915 engine and shows the 2 screw version.  

Cheers

Thank you, Rotax Wizard. My 912iS was built mid 2014 so I believe it would have the single adjustment screw, right? Did the factory use red Loctite on this? If not, it should be possible to carefully turn it without hurting anything. But if they used the red/perm/high strength Loctite, then I would need to heat it up as Roger suggested. Unless... perhaps simply getting the engine warm first and the residual heat around the engine would be enough to warm up the throttle body enough to do the trick.

Bill Hertzel wrote:

As others have shown, The adjustment screw is on the Rear side of the Throttle Body (TB).
The Air filter is attached to the throttle body so it should be obvious where it is located.
As shown on the 915 TB, the screw has a spring under it just like on your lawn mower.
Mine only had some witness paint on it.  No Heat Needed,

The idle screw is about 2 feet behind the propeller.  Use caution!
Approach from the rear along the fuselage. Not from the side. (Assuming a High Wing)
A low wing requires a little more planning.
Make a practice approach with the Engine OFF to avoid any surprises.
Keep the screwdriver in your Right Hand and keep your Left Hand firmly on the plane to avoid tripping.
The door or window frame is usually a good place to grip.
There is no reason that ANY part of your body needs to be closer to the prop than the rear of the engine. (3 ft.?)
Always move slowly and deliberately.
When changing sides, Always walk around the Tail.  Respect the Prop!

Tie the plane's tail to a tree or a car. A Tow hitch is ideal.
Use a rope rated for at least 1000 lbs.
2 loops, 4 strands of 3/8" rope should be enough.
With the cowling already OFF, start it up, Warm it up. Then set it to idle.
Turn the idle screw 1/4 turn at a time. CW = Faster, CCW = Slower.
When reducing the speed, the idle may not change until you cycle the throttle once.
Rev it up slightly and then pull it back.
Repeat as needed.
Obviously, this is easier to do with two people, but either way, you MUST tie the plane!  Respect the Prop!

Thanks, Bill. Any reason this needs to be done with the engine running? Why not just turn it on, idle for a few minutes at 2500rpm, shut down, then turn the idle screw clockwise half a turn, then start back up and see where it's at? 

Mission accomplished. I have a 2 screw throttle body. Turns out my idle screw wasn't even contacting the throttle cable at all and it was fully backed out. Which explains why I was getting the minimum idle the engine is capable of. I had to turn it clockwise SIX and a half times, plus a ⅜ turn, so just ⅛ of a turn shy of 7 turns and now I'm sitting right at 1,750 idle. I decided to take the safer option and made each adjustment with the engine off. So I had to restart the engine 4 times in total within 5 minutes to make the necessary adjustment, but I felt that was better than the risk of getting my head within 2 feet of the prop. That probably would have been a pain on a non-FADEC engine with the repeated hot starts, but a non issue with the iS! 

One interesting thing of note is the shutdown is *much* smoother now. It used to let out a big shudder when I'd turn off both lanes after bring the throttle to the idle stop (I was instructed to always bring throttle to idle stop before shutdown). But now with it shutting down at 1750 rpm instead of 1470rpm, there's no big shudder and it just smoothly shuts down! 

Thank you for all of your help on this, Bill, Rotax Wizard, and Roger.