Rotax 582 not revving high enough

[Pag]

I have a blue top fitted with an Ivoprop ground adjustable 3 blade prop. Even wìth the prop fined, we can't get over 5900, which then drops to 5400 over 10sec. Fuel pressure good (Facet fitted for boost) needles and jets correct, plugs 2 hrs old, pots give full lift. Tried bigger main jets - no go. Pipes all new and tight. Getting despondent. Anyone help?

[avidflyer]

Did you do a fuel flow test? Maybe it's starving for fuel at highest fuel burn. What are your egt temps doing during this time? JIm Chuk

[Navycposd]

just spitballing ideas here....

Is this a new prop on this engine? Did the engine make power before and now it doesn't?
What would make you think it needed a prop adjustment other than low power RPM?
Once I set my last IVO prop, it didn't get adjusted in 8 years (even removing and installing it every 100 hours)

Are you sure both slides are opening at the same rate? (throttle cable issue? Oil Injection cable issue?)

Try something simple, remove the air cleaner and try without it. A dirty cleaner can restrict wide open RPM

Did you try with the boost pump off; just running on the pulse pump?

At what throttle setting do you reach max RPM? As you advance throttle beyond max RPM, what happens to the engine? Change in temps? CHT rise indicating lean or CHT drop indicating rich?

[Pag]

Did you do a fuel flow test? Maybe it's starving for fuel at highest fuel burn. What are your egt temps doing during this time? JIm Chuk
sorry for the late reply chaps - I've been unwell, but better now!
Fuel flow has been tested and is adequate. egts are wel within parameters - c.70 degs
Thanks for your questions.

[napierm]

Idiot question but I don't know the history of the engine. Is it new? New to you? If not has it had the 150 hour top de-carbon done?

If not, can you look in the exhaust ports and verify there is no galling/scratches on the cylinder walls? Is there a nice even cross-hatch pattern or are there shiny spots where the pattern is nearly gone?

We just had a guy who lost power on his 532 with cylinder galling. Plane was a total loss but he was unhurt. Lucky.




I have a blue top fitted with an Ivoprop ground adjustable 3 blade prop. Even wìth the prop fined, we can't get over 5900, which then drops to 5400 over 10sec. Fuel pressure good (Facet fitted for boost) needles and jets correct, plugs 2 hrs old, pots give full lift. Tried bigger main jets - no go. Pipes all new and tight. Getting despondent. Anyone help?

[napierm]

Another question: What size are your idle jets?

What you are describing here the idle jets should make no difference. On my 582 it would load up on taxiing and quit. Would quit on final too. Turned out the stock #55 jets are way too rich. #45 jets cured the problem along with Iridium spark plugs.

Do you have an EGT gauge on the motor?

1200 degrees is right on the edge of burning the rings.
900 is too rich.
1000 to 1100 is what I targeted and seemed to be about right. Good power and the plugs didn't carbon up.

Are you warming up the coolant to (I can't remember what) degrees *before* going full power? I had to keep some power in my engine to keep it warm while coming down from altitude.

OT: One day I was coming down and it was very cool and gusty. I rode right rudder to slip it down so I could keep power in to keep the engine warm. Batted around by the wind pretty good on downwind and final. I've got the cowl off and this cop drives up. Asked if I've just landed. Seems someone called 911 to report what they thought was an accident. I was thinking that if to the casual observer my approach and landing could not be discerned from a crash in progress maybe I should improve my skills....



I have a blue top fitted with an Ivoprop ground adjustable 3 blade prop. Even wìth the prop fined, we can't get over 5900, which then drops to 5400 over 10sec. Fuel pressure good (Facet fitted for boost) needles and jets correct, plugs 2 hrs old, pots give full lift. Tried bigger main jets - no go. Pipes all new and tight. Getting despondent. Anyone help?

[Pag]

Thank you all for your questions and suggestions.
I bought the plane G-BPKK two years ago before I got my licence, and have done a fair amount of work on it.
It is only this year that `i have been in a position to do tailwheel conversion lessons, but we found the engine to be underpowered.
The engine has on it 297 hrs, and has undergone decarb at 150hrs (according to the log). Fuel flow is good. EGTs at present (cool spring) are below the max 80 degrees (c. 65 constant flat out with no observable change or imbalance). Bing stock idlers fitted, and new NGK plugs correctly gapped (I am told is 20 thou?) - although the spark appears very small to my 4 stroke vintage car engine eyes. I am afraid 2 strokes are a bit of a new thing to me.
i have tried the elec pump on and off - no change. Air filter is already off. Pistons lift simultaneously, no cable problems.
Chaps at my club suggest trialling a borrowed prop - the pitch setting of one of the bldes appears to be 2 degrees different to the other two - can this have that much effect?
I shall remove the exhaust manifold and have a look as suggested, napierm.
Thanks again for your comments.
Pag

[Navycposd]

Thank you all for your questions and suggestions.
prop - the pitch setting of one of the blades appears to be 2 degrees different to the other two - can this have that much effect?
Pag

Absolutely! Prop blade out of blade adjustment can cause the engine to not make RPM.

[avidflyer]

Absolutely! Prop blade out of blade adjustment can cause the engine to not make RPM.

It would for sure make some vibrations if one blade is different that the others. Another question is how accurate is the tach. A tiny tach is very accurate. Not always the case with some of the original tachs that were put in these planes JImChuk

[Pag]

Absolutely! Prop blade out of blade adjustment can cause the engine to not make RPM.

Thank you navycposd. I shall give this my focussed attention. We have no tractor 582s in the hangars, but do have pushers. Would using one of these achieve the aim (obviously with the restraining tether acting opp. to usual)?
Pag

[napierm]

You can use a protractor (Warp Drive make a good one) to compare and set all the blades. A digital level (iPhone) works too. There is a trick of using a yard stick on the back of a blade to mark a spot on top of a cardboard box. Then do the same thing with the other two blades. You can absolutely nail the blade pitch matching that way. Also use the box to look at the tracking on each of the blade tips WRT each other.

Please do look at the cylinder walls. At 300 hours Rotax wants you to do another de-carbon (and replace the crank).

It bothers me that the engine RPM sags after 10 seconds.

[avidflyer]

I use a laser to set the pitch on props. Super accurate. Here is a video I made showing how it's done. JImChuk

laser prop setting tool - YouTube (https://www.youtube.com/watch?v=c9Uj_d3uSWc)

[Pag]

Absolutely! Prop blade out of blade adjustment can cause the engine to not make RPM.
Hi, navycposd,
Thank you for the heads up.
We fined the prop off almost completely, and hey presto we have oodles of power and it goes like a rocket!

It might be that at coarser pitches the errant blade is increasing its own pitch , thus increasing load and slowing the engine?
Anyway, all good now and airborne.