FIRST START

[Lizard Lips]

Ran my IO-390 today for the first time! Started on the 3rd blade. However it was not without problems.

1. Ran very, very rich. Had to lean the mixture a lot just to get it to idle. Was able to richen the mixture as RPM's increased but had to lean it again once I began reducing the throttle. Does anyone have the procedure for adjusting the injector mixture?

2. Hartzel prop would not cycle. I think I ran the engine long enough to fill the prop cylinders with oil, but I'm not sure. When attempting to cycle the prop, nothing happens. RPM was about 1600 at the time. Any suggestions?

3. No manifold pressure indication. However I believe this is an instrument problem rather than an engine problem. Dynon Skyview HDX system.

Joe
Longview, Texas

RV-14A 95% complete, 95% to go
Arion Lightning LS-1 Flying regularly
2020 Dues Paid

[BillL]

Keep running and the prop will cycle, it took a while for me, and more than 1700. Maybe 10 min, don't remember exactly but I was beginning to think something was wrong.

Don't pump the prop speed back and fourth just pull it and leave it until it responds. Now BE CAREFUL, the plane can jump chocks when it bites.

Tie the tail to a car, truck, tree, but tie to something. Thrust can be 800 lbs.

[lr172]

Originally Posted by Lizard Lips

Ran my IO-390 today for the first time! Started on the 3rd blade. However it was not without problems.

1. Ran very, very rich. Had to lean the mixture a lot just to get it to idle. Was able to richen the mixture as RPM's increased but had to lean it again once I began reducing the throttle. Does anyone have the procedure for adjusting the injector mixture?

Turn the idle mixture screw in 1/2 or 1 turn. Keep doing it until you get max RPM or MIN MAP with the engine warm. You can fine tune it later, just dial it in until it idles nicely for your first flight. Just remember that cold engines want a richer mixture, so when you land with the engine hot, it will run even worse than it did when cold; Assuming a rich idle.

[Lizard Lips]

My thanks to both of you for responding. Good advice! I'll tie the tail tie-down to a stump, or something, as you suggested just to be safe! I only ran the engine maybe 5 minutes and did not advance the rpm above 1500 -1600.

I do have one more question concerning the idle mixture. Is there a diagram, or drawing somewhere that shows the location of the idle mixture screw? I know that sounds dumb, but this is my first experience with a fuel injected engine.

[Rallylancer122]

Is it a new engine? I would be very surprised if the servo is that far off. You might want to look for other issues before messing with it. (How was fuel pressure? )

There is an art to setting up those servos. I know that with a shiny new airplane sitting in the hanger it's going to be a loooooong weekend, but I would be inclined to wait until I could talk to Lycoming or Avstar.

Dennis Martin

[mahlon_r]

The idle mixture on a fuel servo is not adjusted with a mixture screw. There is a turn buckle arrangement on the side of the fuel servo that has the mixture control. In between the two square blocks of the turnbuckle is a wheel that is kept from rotating on its own by a spring that fits into detents on the wheel. Turning the wheel is what adjusts the idle mixture. If you look closely at the blocks, one of them will have a R and an arrow on it. The arrow is pointing in the direction you would turn the wheel to make the mixture richer. Turning the wheel in the opposite direction of the arrow will make the idle mixture leaner. The spring does not have to be removed to make the adjustments. It's purpose is to allow adjustment and prevent the wheel from turning on it's own.
Good Luck,
Mahlon

[lr172]

Originally Posted by Lizard Lips

My thanks to both of you for responding. Good advice! I'll tie the tail tie-down to a stump, or something, as you suggested just to be safe! I only ran the engine maybe 5 minutes and did not advance the rpm above 1500 -1600.

I do have one more question concerning the idle mixture. Is there a diagram, or drawing somewhere that shows the location of the idle mixture screw? I know that sounds dumb, but this is my first experience with a fuel injected engine.

On a Bendix style servo, the mixture is adjusted via a star shaped disc in the middle of the bar that connects the throttle linkage to the idle valve. It is on the co-pilot side and the bar should have an "R" with an arrow next to it, indicating which direction of rotation will create a richer idle mixture. I have no idea what the arrangement is for the FM series servos.

Larry

[KeithB]

I have a Lyc 390 with Hartzell governor - it requires at least 1850 RPM for the prop to cycle. 1900-2000 works best.

[birddog486]

My new IO-360 was the same way.(extremely rich/didn't want to run) You might try turning the wheel one full turn to get in the ballpark and run it again. Once you get close it only takes one click either way to make a significant difference.

[Lizard Lips]

Fantastic! That's exactly the kind of info I was looking for. I now feel confident in (1) locating the adjustment bar and (2) making a change and see what happens. As long as I document the changes I can always go back to where I was. By the way, it IS a brand new engine.

The comments on the prop pitch change are also what I needed. I simply did not run the engine fast enough and did not leave the controller in full pitch long enough to cause a change. I'll tie to a stump, run fast and wait for it to cycle. Bet it does!

Thanks everyone.

Joe
Longview, Texas