582 High EGT'S HELP

[Bluebird19kf]

I just purchased a kitfox model 3 with grey head 582. Engine has 190 hrs. I have no experience with this airplane or rotax engines. I have been seeing EGT'S. At 1250 in cruise rpm of 5800. I have read this is to high so I decided to raise the needle one position to make it richer. Flew it and it climbed out smooth with full throttle but from 4 to 6 thousand rpm it misses and shutters pretty bad. The EGT'S where down around 1100 though. So I moved the needles back to where they were and it runs like it did before, smooth but EGT'S at 1250. What should I do or check. I'm lost.

[avidflyer]

You should check the plugs. They are accurate even when a gauge is not. Plugs should be a coffee color. Maybe run it on the ground for 5 minutes at that cruising rpm, then shut it off without letting it get down to idle, then pull the plugs and look at them. If it's to rich, the plugs will be black, to lean probably gray. At first glance, 1250 is to high, but that is if the gauge is accurate. EGTs are very important. To high, and the motor burns up fairly quick. JImChuk

[Av8r_Sed]

I've had good luck managing the EGT's on my Model III. The key is (1) replace the Westach needle gauges with something electronic and more accurate. I use the MGL E-1 instrument (Sponsor here, click the link on the left). and (2), install a HacMan mixture control from Green Sky Adventures. This gives you in-flight dial control. I still have to avoid running in the mid-throttle range while unloading the prop, but everything else is easily manageable.

[Dusty]

The egt gauges are not accurate so as suggested check the plugs.
Changing needle position will mostly effect mid range with very little effect on wide open throttle.Do a full power ground run and when the egt peaks crack the choke slightly if the engine appears to load up and loose power your jetting is about right,if it doesn't have much effect check the main jet sizes (I assume both cylinders read the same)and also look for debris.if one guage reads high swap the probes.
I hope there' is something of use here.
Cheers

[Bluebird19kf]

Thanks for the help guys. Much appreciated. So today I pulled the plugs and they look brown (coffee colered). Didn't do the run up because my right brake needs bled and cant hold full power and I really want to get some of the goofy stuff that I want to change sorted out. I pulled the exhaust because for one I wanted to paint it and put new gaskets on but to also have a look at the pistons. They look really good no scoring. Pulled the carbs because I want to verify what jets are in them and replace the carb sockets. I want to also do a compression check tomorrow. Also I ordered the MGL E1 because I feel like I could be getting false readings on the needle gage as mentioned. I'll post back up when all that is done. Do you guys think it is necessary to do a pressure test on the crankcase? Thanks again.

[LSaupe]

I had the same issue and it was the gauge (off scale high by like 200F). I also went with the MGL. Slight increase in blade angle (increased engine loading) will help as well (given your static RPM is still in range and your plug color is good).

Pressure test in the crankcase is rather difficult, and two of the areas you would want to verify you cant readily get to (crank seals) due to the gear box and flywheel stator.

http://www.teamkitfox.com/Forums/showthread.php?t=6873&page=2

http://www.avidfoxflyers.com/index.php?/topic/3807-egt-instrument-recommendations/

[Bluebird19kf]

I pulled the carbs apart today and the jets aren't matching up to what I have listed for this application.

Main Jets=165
Idler Jet = 60
Needle Jet=2.68 in one and 2.72 in the other
Jet Needle= 15k2 in both at 2 slots from the top
Air Screw= 1 turn out

The chart I have says they are supposed to be

Main Jets=165
Idler Jet=55
Needle Jet=2.72 both
Jet Needle= 11G2 with clip in 3 slot from the top
Air Screw=1turn out

I'm thinking order all new jets that are recommended and go from there.
What do you guys think?

[LSaupe]

Yep, always good to start with a good baseline. Might want to purchase a set of leaner idle jets as well (like 50's). I am running 50's at 1.5 turns and some guys are running 45's. These are set very rich on the low side.

[Dusty]

We just changed the 45 idle jets in my brothers 582 to 35's all else is standard,on finals the engine is way smoother and the EGT's are now around 1000F instead of 850- 900 on final,possibly less chance of a cold seizure on go round? The original 55 are way rich,but if you run premix maybe stick to the 45's
As on a long throttle closed decent fuel=lubrication.
Don't throw the 15k2 needles away yet.I run these to get rid of a mid range temperature spike on light load decent.

[Bluebird19kf]

Update: so after a month of going thru everything I rebuilt carbs with all new jets to Rotax specs, new ivo 3 blade prop, and mgl e-1. Pitched prop at 6500 climbing out at 60. Now my issue is that when giving it full power at take off it stutters in the midrange until it gets to higher rpm. Also in cruise one cylinder runs 1250 and the other 1150 at about 5600 rpm. I have tried every needle position it really doesn't like full lean or full rich. Any thoughts????

[LSaupe]

How does your exhaust look? Any leaks at the joints or gaskets? Any chance the can is partially plugged? Seems like an odd one. Really shouldn't have to move the needle position by more than one position from stock.

Carb socket health (lack of deterioration and health) is another good thing to look at.

Having one side behave differently than the other almost sounds like synchronization. Double check both slides are at the same position together. Both slide cutouts should reach the top edge of the throat at the same time

Are you confident in your engine RPM? Don't trust the original units they can be off quite a bit. If you haven't done it already toss a Tini Tach on it. Cheap and easy to install.

Other than that it might be an air leak somewhere or maybe a fuel delivery problem. Have you accomplished a compression check recently. If not might be worth a double check.

I pic of your install might help as well.

[Bluebird19kf]

No exhaust leaks or intake boot leaks. I don't have pics but it is either new or done right on that stuff. I don't know if silencer could be plugged. I did think about checking the float level. It is about the only thing I could think of. I did see that the slides open at the same time.

[Bluebird19kf]

I have the tiny tac and mgl which both agree on rpm. Compression checked at 130 both cylinders.

[LSaupe]

Sounds like a tough one. For the slides, it not really that they open at the same time, but where they are in relation to each other when the slide cutaway reaches the top of the throat. Usually just advance the throttle until the first one reached the top and make sure the other one gets there at the same time.

Other things to look at if you hadnt already,

Pulse line on your fuel pump. Make sure that it is the correct material (this is different than standard fuel line). Sometimes it can get soft and flex the tube vice the diaphragm in the pump and make the pump behave badly at times or lower its capacity.

Pulse line length, should be as short as possible

Pump diaphragm, these can sometimes leak enrichening the pulse side of the engine or if it pumps air into the fuel pump cause other issues.

If you have clear carb fuel lines installed do a ground run and make sure you dont see any bubbles coming through downstream of the pump.

You mat have already done this, but always worth swapping the carb positions to see of the problem moves with the carbs.

Has the engine ever been through a rebuild? If so, might be work finding out more of those details. Not sure if an improperly indexed rotary valve would behave in this manner. Just odd that one EGT is higher than the other by 100F. How does it look at other throttle positions? Say from 4500 through 6500.

Yep, float height could be a player as well, as well as needle and seat.

You might have noticed that there was a float recall recently for those carbs. Make sure your floats are still floating fully and that you have the newest floats. I had an issue with that problem. New floats helped a great deal. Also installed new needles and seats.

[TY2068]

Have you ever tied the plane down securely and run the engine wide open to see what max static revs are ?

[LSaupe]

Here is further detail on the floats:

A NEW Alert Service Bulletin has been issued which applies to a very limited range of 912, 914, and 2-stroke engines, as well as any engines which have been equipped with ROTAX part number 861185 floats during engine repair, maintenance or general overhaul as of May 09, 2016.

Due to manufacturing deviations, certain 861185 carburetor floats supplied as spare parts after May 9th, 2016, and/or installed on specific serial number engines and carbs (see the ASBs for specific serial number ranges), may have the outer surface "peel" or “flake” from engine vibration.

Serial number ranges are detailed in ASB-912-069 / ASB-914-051 (certified engines) and ASB-912-069UL / ASB-914-051UL / ASB-2ST-003 (UL engines).

Affected floats must be replaced with current-issue 861185 floats, which are now marked with three dots for positive identification.

http://www.rotax-owner.com/en/videos-topmenu/expanded-video-instructions/459-asb912069

[Bluebird19kf]

I think I figured it out. I found that the choke cable on the one carb was to tight allowing it to be engaged a little. I fixed that and it appears to be way better. Egts match and do not exceed 1200 at any rpm. It is still rough at lower rpms but I believe I may be able to solve that with tunning the pilot jets and airscrews??? I'm waiting for better weather for more testing.

[Bluebird19kf]

It fixed the stumbling in the midrange completely. I have it pitched now for 6200-6300 on climb out. Is that about right?

[LSaupe]

Seems a little low on climb out (maybe more like 6400-6500) though I know some who run there. Anticipate it to run rough below say around 2500 rpm. I only go below during shut down and initial start up then bring it up to 2500 to stop the gearbox chatter.

[Bluebird19kf]

Roger that. Right now it is a little rough up to like 3200 but I have in 60 pilots while troubleshooting. I have 45's I think I'm going to try. That should make that better right?? That also g with air screw adjustment. How many turns are you running.

[LSaupe]

Yep 45s will help alot. I think I am using 50's at 1 & 3/4 turn

[TY2068]

You may be a bit over-pitched. Static on my grey head is 6,200 with 72" IVO 2 blade med 3:1C. Some guys set a tad lower static.

Unless you have the RK-400 clutch forget about it. Anything much below 3,000 and it's rough and chattering. No vibration with RK and 2,000 idle.