First Engine Startup

[jiott]

I did my first 912ULS engine startup today. The engine was purchased 2.5 years ago for my kit and it started up today after only about 3 seconds of cranking with choke on. Fired up and ran nice just like it had been used regularly. Oil pressure came up immediately and all gauges looked good as it warmed up. All my Dynon supplied engine sensors seemed to be reading correctly right out of the box. After oil reached 122 F I shut it down and did the lifter check per the book and all was OK. Of course I had previosly done the oil system purge with air pressure per the book. All looks well and I am ready to do the pneumatic carb sync next. I was surprised how smooth it ran with just a careful mechanical carb sync.

Factory idle setting was right at 1800 rpm. They say you can go as low as 1400 rpm. What idle setting do you guys use?

Max WOT rpm was 5300. Just a little high- recommended is 5150 rpm. I set my ground adjustable blades just like the factory said to do it and it came out real close (5300 rpm) on the first try. I just need to tweak the blade angle to just a little more coarse to get down to the 5150 rpm.

All in all, a very satisfying day after being very nervous about the first start.

Is there any break-in procedure for these engines? I can't seem to find anything in the Rotax literature about it. I know they are run in on a dyno at the factory, so maybe the break-in is already done?

Jim

[Dorsal]

What a great feeling, I would rather start with the WOT a little high than a little low.

[Pilot4Life]

Jim, I can't comment on the ROTAX stuff, but great to hear that the first start was so successful and uneventful! Can't wait to read of the first flight and see the videos and/or pictures! Congratulations on this milestone!

[DesertFox4]

Congrats on the Rotax first start.
No break in procedure that I'm aware of other than keep it under 5800 revs
on take off and 5500 or under continuous operation.
At 5300 rpm static you may be able to redline or more in straight and level flight. Just keep an eye on your tach if first flight is at this setting.
With my 3 blade Patriot Ivo my full power ground static rpm is about 5080 rpms. I can get to 5700 in level flight.

I have my idle rpms set at about 1200 or so only so I can slow it down on final. With air loads on the prop it does not seem to affect gearbox noise.
***Just watch if you do set it around 1200 rpm that you don't pull hard on the throttle while on short final and kill the engine. Maybe 1400 or 1500 rpm would be a good starting point for first flights. Less likely to kill the engine on final.

I am very careful to keep it above 1500 on the ground so as to stay out of the gearbox chatter range.

[Slyfox]

I know, I know, I'm the odd ball. I have my rpm set to about 400. Ha Ha, I knew that would roll some eyes.

I like to dive down to the runway, and with any higher idle, she won't do it. do I run it there on the ground, no way. I have a friction lock throttle and I know right where to put it and know the feel and sound. What does an idle like that do for me. well it keeps me from coming in to fast for one. I'm a proponent of diving in to land, very fun. It also allows me to shut off the airplane with no kick back what so ever. when I go and shut my engine off I back the throttle all the way off and hit the mags off. nice smooth shut off. if any of you know what happens when this engine bucks and farts on shut off, you know when a smooth shut off happens, the carbs stay intacked.

Next is start up, with the throttle all the way off and crank it with the mags off for about 3 seconds and choke on will set you up for a nice start. Now all you have to do is turn the mags on and as soon as it hits advance the throttle to normal idle 1800, nice and smooth with no kick. again the carbs stay in place and don't fall off or crack the rubber in front of the carbs. I've been doing this for over 1000 hrs on the 912. works for me. My best advantage of the lower rpm is the ability to do short approaches and be able to control my speed. all I have to do is add just little throttle before touch down.

[jiott]

Thanks guys for all the good info.

Jim