Rotax 582 consumption

[Olle1975]

Those plugs are looking pretty carboned up for 25 hours, not quite at the light tan color that's desireable. What is your EGT in cruise, and what type of instrument are you using to measure it?Also, are you premixing oil or using the injection system?Is this the condition just after returning from a flight, or was there considerable ground running time before you shut down?

In the pic the colour is a little bit darker than real, the color is between brown and light brown, I think, it's pretty good.

In cruise I have about 1150F and I use the rotax EGT instrument to measure it.

It's an injection system and it burns 13-14L/hr during flight at 5500-5800rpm

The condition is after a flight about 50 minutes before shut down.

http://www.cfisher.com/152hournkg.html

It works more hot (EGT) than mine, isn't it?


Olaf

[Dave F]

Looks like you doing ok -- You mixture looks ok not ideal but OK is good.

Leave it alone or run 50F hotter.
I am betting that you are running at 1150F
and OAT is likely close to freezing out 32f - 0 C or over 5000' asl

[Av8r_Sed]

Yup, I think you're good then. The 50 minutes of ground run would explain the slightly oily appearance.

[Olle1975]

Not ground run, 50 minutes flight....

[Danzer1]

Olaf,

The end of the electrode looks pretty good.

Towards the base of the electrode, insulator and the bottom ring of the plug look to dark. If it is dry black - it is carbon build up (still rich). If wet black it is oil (worn rings and/or pistons).

What kind of fuel are you running?

[Olle1975]

Thanks for this sights of indication. I'm sure the dark area is dry, I have had seen if it's wet. My engine run with unleaded ROZ 95.
The engine runs not more than 42 hrs and I have cleaned the rings for 4 hrs. The lower ring was fixed, so the sparks runs about 20 hrs with a fixed lower ring. Before the engine have had a break about 10 years, but it runs well the last 25 hrs.

Olaf

[Danzer1]

Olaf, It looked like carbon to me too, it really isn't to bad. If it is running well and your temps and fuel consumption are in line, I might just keep an eye on it for a while.

Carbon on the base ring is a rich idle setting. Usually idle air screw adjustment - 1/4 turn at a time or at worst the clip position on the needle - up one notch for leaner.

Greg

[JimS]

Looks like she's only firing on "one"!

[Olle1975]

Carbon on the base ring is a rich idle setting. Usually idle air screw adjustment - 1/4 turn at a time or at worst the clip position on the needle - up one notch for leaner.

[Danzer1]

Only way to tell if that will do it - is a few runups at idle only - seeings that's where the issue is (not flights) with clean plugs, quick shut down, let them cool and inspect the plugs again. Readjust and retest until you get a consistent light tan across all parts of the plug.

When testing plugs it is critical to only run to the speed you are testing and do a throttle chop and shut down to see the plug condition at the desired speed (in this case idle).

If adjusting the air screw does not get it to where it needs to be, you might try up one more on the clip (assuming the needle and idle (pilot) jet have never been messed with.

What also could possibly cause rich idle, is an incorrect float height, not often, but it happens.

I tune my bikes for hours to get them just right for each season and for my Denver altitude and it takes a lot of time (same kind of carbs). Since then I've acquired a Colortune. Google it - very rare and hard to find, usually NOS - but you can't use it on an aircraft. In a nutshell it is a clear plug so you can see the fire while you rev through all throttle settings and tune to the optimum color fire in the cylinder (fuel/air ratio) - it is way cool!

Good luck