582 0verheating issue

[pudestcon]

Hi Ian,It's john from west swan.Finally managed to join up.Have been doing a bit of research re my thruster prop.Should be 6200 Max static rpm and flat out in straight and level flight 6500.From what I've read max red line should only be possible in a descent.So much info out there but this seems to tally with the old Victa.Max straight and level was 2550.2800 red line only possible in a dive.Fitted those doors yet?

G'day John,

Glad you finally got sorted so we can talk to you here. You are definitely correct, from what I have read about max revs; problem is I can only get 6200 absolute max, although have not tried increasing revs in a dive or descent. I would be happy to get the expected 6500 when flying. I haven't fitted the doors yet but they should be good once I make the modifications. I'm going to remove the polycarbonate, alter the frames and fit new polycarbonate. I have some things to do before that though, as you may have gathered from this thread!!

 

How are you going with your Thruster project, you can't use the weather as an excuse anymore John! Have you thought anymore about that prop balancer we were discussing last time we spoke?

 

Pud (you can call me Pud, John. I won't hold it against you)

 

 

[pudestcon]

Pud, If your only running 12 deg blocks and not getting the rpms, then it doesn't sound like the pitch blocks if everyone else is running 15 and doing ok. I think you do need the high radiators to keep your temps down, and the correct coolant. Are you using Castrol anti-freeze, anti-boil mixed 50/50 with demineralized water, as recommended by Rotax for that engine ?. The right coolant is a big thing on those engines.Also remove the air cleaners from the carb, put the throttle at full and stick your finger in on the slide, see if you can push it up any further. If not adjust the brass nurled knob at the top to raise the slide all the way at full throttle. The needle needs to be fully up through the main jet for a full flow of fuel at full throttle. It is only the main jet that meters fuel at full throttle. Yes your Gbox/ engine rev calculations are correct. EGTs should run between about 1100-1250 deg farenheit, 1150-1225 is perfect. Don't go above 1250 if you can help it. Have you gapped your plugs correctly, they come out of the box new at 25 thou but run better at 22-24 thou....Coolant temp is what you watch on these engines and the range is 60-80 C. Mine always sat at 70 C with the thermostat fitted. Silly question..but I am assuming you do have 100mls of 90 wt oil in the gear box ?..as required.......................................................Maj...

G'day Maj and thanks for your post,

I'm not using Castrol anti-freeze brand (the brand escapes me right now) but what I'm using does meet the specifications as per Rotax requirements, mixed 50/50 with demineralized water. I believe it to be the radiators as well - next weekend will prove/disprove the theory. The plugs are gapped correctly with new plugs installed at my last visit. According to my operators manual the gearbox oil should be 85W140 grade which is what I had in it, until Pol suggested I change to 90 grade oil, which I did. Didn't make a difference in any way that I could see. I filled the gearbox until the oil started flowing from the lower screw hole, as per the Rotax instructions in the operators manual. All your other comments are taken on board and are correct on my machine. I will be removing the carbies for a clean and re-adjustment to ensure all is correct. I have made up a simple manometer from clear plastic tube to check syncronisation of both carbies once re-installed on the engine.

 

Cheers and thanks Maj,

 

Pud

 

 

[pudestcon]

I thought 930-1150 is operating temp, 1150 1200 is caution range

G'day Tex,

In my Rotax operators manual on page 10-1 it says, for the 582 UL DCDI/mod. 99 (Blue head) that normal egt operating temps are in the range 930-1150F, max 1200F. So mine is running well below max.

 

With the max revs of this engine, my manual says on page 10-1 take off speed 6800 RPM max. 5 min, cruise speed 6500 RPM

 

I have a Rotax Repair Manual as well, that states similar numbers to those I have quoted above.

 

Pud

 

 

[Guest Maj Millard]

Pud, only mentioned the Gbox oil unless you had forgotten to put some in!... Type of oil shouldn't make any difference, sounds like you filled it correctly. A lot of the working 582s that I see out bush (summer temps 40+ C) will run a third radiator usually below the engine, this gives both a better cool when working hard, and additional coolant capacity. I too believe your radiators may be the drama here, but that shouldn't stop you running the correct Max rpms. Static on the ground tied down you'll only get around 6400-6500 but moving throught the air you'll always pick up another 2-300. My old Drifter with 4-blade Brolga (17 or 18 pitch blocks) would easily turn 7000 on take off if you let it, and it was only a grey top. I never had any cooling dramas with it in 650 hrs...............................................................Maj...

 

 

[bones]

hey pud, i know i have not read this thead in its intirety, but for a 68" prop on the 65hp motor, pulling 12* hmmmmm

 

ok well i got a 100hp rotax pushing a 68" WD 3 blade prop, and it will only pull 11* only rev to about 5300rpm

 

i got a 914 rotax with a 70" Ivo 3 blade medium prop with about 12* and it only revs to about 5400rpm

 

All these * reading were right at the tip of each blade.

 

Seems to me your trying to get it to pull too much air, i think dont quote me, but there is a Xair at YCHT, running a 68" 3 blade brolly with a 618 on it and i am pretty sure the pitch at the tips of the prop is only like 7*

 

Now i will be perfectly honest and say i dont know where these pitch blocks take there * reading from, but just for sh*ts and giggles put a bubble on the prop and see what you have right at the tips and compare.

 

 

[Guest Maj Millard]

Bones, blade pitch angle is usually measured at the 75% point on the blade, or wherever the manufacturer recommends....some are measured at the 50% point, but personally I go for the 75% point when I'm repitching. Are you coming to the Bluewater Park fly-in BBQ north of Townsville next Saturday 5th May ?....Cheers........ Maj...

 

 

[SAJ]

Thanks SAJ. Good to see you worked out how to load photos - it's not too hard once you get the gist of it.Your solution to the overheating problem is certainly novel, and obviously working. I like the idea of shutting off the lower radiator when its not needed - I hope it is attached well!!

Cheers, Pud

G'day Pud

I fitted the third radiator back in 1996, when I was running in my engine a friend of mine told me that 80c was red line, he said the VDO water temp gage was a car temp gage, I was glad he told me that at that time because I had been running my engine for about 10 to 15 minutes at different throttle settings. I thought this is taking a long time to warm up and get into the green arc, the water temp was just getting to 80c when he told me 80c was red line, I droped the revs back to idle and shut down the engine and let it cool down, when I started flying my Thruster it was in the summer and the temp got up high all the time, thats why I put the third radiator on and its been good ever since. In the winter it would run to cool so I put a plastic cover over the third radiator to keep the temp up, it was a bit of pain if I went for fly on a warmish day the temp would get a bit high so I would have to land to take the cover off, So before I flew to Raglan flyin in June 2005 I made a ajustable flap to cover the radiator, and its been working great,

 

SAJ

 

 

[bones]

Bones, blade pitch angle is usually measured at the 75% point on the blade, or wherever the manufacturer recommends....some are measured at the 50% point, but personally I go for the 75% point when I'm repitching. Are you coming to the Bluewater Park fly-in BBQ north of Townsville next Saturday 5th May ?....Cheers........ Maj...

Yrah i thought it changed, i guess it doesnt matter where as long as the same on each blade.

sorry Maj, im back in the NT again for the next 6-8 months

 

 

[flyerme]

Hey Pud, you gettin it sorted? I had revs probs you may recall (NOT over heating though) after a re-pitch managed the factpry recomended static=6200rpm and cclimb is 6500rpm,good luck

 

 

[pudestcon]

Hey Pud, you gettin it sorted? I had revs probs you may recall (NOT over heating though) after a re-pitch managed the factpry recomended static=6200rpm and cclimb is 6500rpm,good luck

Next weekend flyerme, hopefully.

I've been following your progress with interest, including your c of g issues.

 

Cheers,

 

Pud

 

 

[pudestcon]

Another thought - yeah I know I do that too much sometimes!!

 

I was reading in the CPS (California Power Systems) catalogue Mike Stratman's "The Proper Care and Feeding of the Rotax Engine" last night, and he mentions using the "enrichener" (choke) circuit for diagnosing problems with carburettors. Do you think it would be worth trying with my problem? I was thinking that I could fly along with my max 6200 revs and see what activation of the choke does. I'm thinking if the revs increased with activation of the choke it would indicate a lean condition, maybe caused by smaller than required main jets.

 

Waddayareckon? Also, I'm thinking I'd just use a bit of choke rather than activate it all the way, yes?

 

If you want to read this article, it is called 'Tuning the Bing Carburetor Understanding the Mid Range'. Part 11.

 

Pud

 

 

[flyerme]

Another thought - yeah I know I do that too much sometimes!!I was reading in the CPS (California Power Systems) catalogue Mike Stratman's "The Proper Care and Feeding of the Rotax Engine" last night, and he mentions using the "enrichener" (choke) circuit for diagnosing problems with carburettors. Do you think it would be worth trying with my problem? I was thinking that I could fly along with my max 6200 revs and see what activation of the choke does. I'm thinking if the revs increased with activation of the choke it would indicate a lean condition, maybe caused by smaller than required main jets.

 

Waddayareckon? Also, I'm thinking I'd just use a bit of choke rather than activate it all the way, yes?

 

If you want to read this article, it is called 'Tuning the Bing Carburetor Understanding the Mid Range'. Part 11.

 

Pud

Hey Pud,I came across this also a number of times from dif ferent sources,including bert flood inports,and tried it. DO NOT TRY IN AIR....Please do it on a ground test, first Your engine will more than likely die due to flooding and yes apply a small bit of choke at a time but almost gareenteed the engine will stop! let us know . take it easy pud

 

 

[pudestcon]

Hey Pud,I came across this also a number of times from dif ferent sources,including bert flood inports,and tried it. DO NOT TRY IN AIR....Please do it on a ground test, first Your engine will more than likely die due to flooding and yes apply a small bit of choke at a time but almost gareenteed the engine will stop! let us know . take it easy pud

Yep!! Agree with you flyerme - do it on the ground is the way to go.

Thanks

 

Pud

 

 

[turboplanner]

Pud, you have the possibility of wrecking the engine using well meaning anecdotal ideas.

 

Major showed how to make sure the Carb slide needle is out of the orifice.

 

When that test is done, and that issue eliminated, then the main jet tube is unrestricted.

 

That leaves only the main jet size as a potential cause.

 

The main jets will be stamped with numbers.

 

All you have to do then is compare the stamped number with the correct number shown in the engine specification.

 

If the numbers match, that is what Rotax tested on many engines to get an optimum mixture ratio.

 

What some of the other guys are talking about is playing around with jet sizes where there is no specification.

 

Since your investment is more that $16,000.00 that would be a very expensive play.

 

So that's the safe path to check mixture except for one other thing.

 

Some people, wrongly, believe it's a good idea to run an oil mix in the fuel when running the engine in.

 

The reason I say wrongly is that you are no longer flowing petrol, but a less viscous mixture which slows the volume squeezing through the main jets and runs the engine lean!

 

Quickest way to fix that one is drain the tank, drain the carbs and clean out with petrol.

 

 

[David Isaac]

Correct me if I am mislead her Tubz and Nev,

 

I have always believed a simple way to determine whether a 2 stroke is running lean at full power is to ground run the engine at wide open throttle for a few minutes and then turn off the fuel. As the engine runs out of fuel it will lean out and if the mixture is too lean, there will be no increase in RPM just before the engine dies, it will just stop. If the engine is running with the correct mixture at WOT, as it runs out of fuel it will lean out and momentarily increase in RPM before it stops.

 

Of course this is a safe practice because you are ground running in this test.

 

Regards,

 

 

[fly_tornado]

I haven't heard of that system, I always thought you looked @ the spark plugs. On the insulator, idle is the tip, midrange is the middle and the base is WOT.

 

 

[facthunter]

That would do it David in a rough sense. Hard to quantify it. I recommend the loaded engine be run with no aircleaners and carefully place yourself in a position where you can obstruct the intake with your fingers., thereby enriching the mixture.. If it improves it was too lean and if it immediately gets worse it "could" ( would), be too rich.. I think the generally accepted method is by the EGT's. You would have to "prove" them to be sure. ( Remove from another motor. The position in the ex manifold will affect the reading.

 

IF you have the right plug(s) correctly tensioned the colour ( IF you know how to read it correctly) will give you an indication. Works best at high throttle settings with a quick cut straight after. ( If you idle for any time you will alter the look of the insulator). The plug must be the right heat range. Plug colour is more a test of the right plug than a mixture check. Nev

 

 

[Guest Maj Millard]

Pud, and others, the 'choke' on the bing carbs is not a choke at all, inasmuch as it doesn't restrict airflow in the common choke fashion, to enrichen the mixture. It is more of an enricher valve which opens a small orifice with the 'choke' activated and allows a little more fuel in.

 

If you have all the carb settings etc as per Rotax recommendations, including the correct main and other jets fitted, and you then don't achieve correct RPMs than it is not the carbs !.....look elsewhere.............................Maj...

 

 

[farri]

What Maj has said on the "Choke" is correct!...To get maximum effect from the enricher valve/s, the throttle must be fully close when starting the engine.

 

Frank.

 

 

[pudestcon]

Well my post #111 certainly pushed a lot of buttons:smile: Thank you for the responses, I appreciate them all.

 

Be assured, I will be taking the investigation in a slow, orderly fashion - and I will leave out the choke/enrichener idea. It's not really relevant in my situation, as explained by maj in his post #118.

 

Roll on the weekend....

 

Pud

 

 

[pudestcon]

Pud...I know it may sound simple we must start at the basics :- "Have you changed the radiators out too, the blue heads need a larger radiator than the grey heads".

there is my .25 cents worth.

 

Keith Page.

And the winner is Keith Page!!! Thanks Keith. I tried everything else conceivable as discussed in previous posts but the high temps remained until I changed to the larger radiators - thanks for the lend of your radiators Riley, much appreciated.

The 6200RPM max issue is still current though. I tried all ideas put forward, checked the carbies (simple concept aren't they?) including pulling all jets and needles. All is as it should be with 165 main jets, needles under the white plastic spring cups, and the slides operating through the full range and in syncro with one another. I think I might have to accept defeat on this one:see no evil:Maj Millard says if the carbies are correct then look elsewhere - meaning the propeller, and has been suggested, I could source a known propeller to check what that would do on my setup. I'll see....

 

Thanks everyone for your contribution, I'm gonna let the situation sit for a while now, and enjoy a bit of flying without too much tinkering. Although I need to acquire the larger radiator assembly as the one I used this weekend is on loan from the very generous Riley. Thanks again Riley, I appreciate your help and good humour in allowing me to use your radiators for this little diagnosis exercise.

 

Pud

 

 

[David Isaac]

Well done Pud,

 

If you could borrow a prop from another identical model 582 that is pulling the higher RPM and place that known prop on your engine, I am sure that would identify if there is a problem and where it would be.

 

 

[robinsm]

Pud, if the aircraft is performing close to what the others are (forget the 6800 rpm limit - I have never acheived it) accept it and enjoy flying. I have 700 hrs on an old grey head second hand engine, and then 100 hrs on a new blue head engine. I blew a hole in one of the pistons of the old grey head trying to get the "text book" figures. If the jets are as recommended by floods, and the carby setup is as recommended, the egt's close but a little low, accept it and enjoy flying the aircraft. I( just put 26hrs on mine over 5 days and the motor never missed a beat and performed well.

 

I tried all sorts of changes and wound up back at the motor setup as per floods and the propeller pitch as per the recommendations of the propeller manufacturer/distributor site. (I run a 68inch 3 blade brolga with 16 degree pitch blocks through a c box 3.1 ratio.)

 

If its close, fly it.

 

Just my 0.2c worth.

 

 

[turboplanner]

What colour were the plugs Pud?

 

 

[pudestcon]

What colour were the plugs Pud?

Tan/brownish but on the lighter side. EGTs with a 50# spread at 1100* when at 6000 RPM

Pud