Hello from Argentina!

[Lucas Di Pentima]

Hi all, I'm a fairly new ultralight pilot, based on Santa Fe - Argentina.

 

I own a Flightstar 2 seater with an old Rotax 532 that's giving me some headaches, I'll be surely posting some questions about it. I'm planning on replacing it with a HKS 700E in the near future :)

 

Best regards

 

 

[kaz3g]

Hi Idipenti

 

Welcome to the forums. I know zilch about 2 stroke aero engines but there are many here with heaps of experience with them and I'm sure they will offer the benefit of their knowledge to you.

 

Kaz

 

 

[Head in the clouds]

Hi Idipenti,

 

Welcome to the forum

 

Cheers,

 

Alan

 

 

[eightyknots]

Hello Idipenti, :welcome:to the Forum

 

 

[Lucas Di Pentima]

Thanks for the warm welcome :) Are there any ultralight pilots in this forums?

 

 

[Gnarly Gnu]

Hola Idipenti! (Bienvenido I think it is?)

 

Are there any ultralight pilots in this forums?

One or two....

 

 

[Lucas Di Pentima]

Great! I felt that the ultralight world was being left behind in favor of the new LSAs, at least that's the feeling when I read some GA magazines out there. Here in Argentina the LSA class is just recently being created.

 

 

[Lucas Di Pentima]

This is my bird, actually now is fully painted so it's prettier :P

 

 

 

[Phil Perry]

Hi all, I'm a fairly new ultralight pilot, based on Santa Fe - Argentina.I own a Flightstar 2 seater with an old Rotax 532 that's giving me some headaches, I'll be surely posting some questions about it. I'm planning on replacing it with a HKS 700E in the near future :)

 

Best regards

Hi Idipenti,. . . . That's not a bad engine you've got there, . . . .I am sorry to hear that you are having problems with it. I've always found it to be a good powerplant,. . OK, it's only got single ignition, but it has plenty of power, and is usually fairly reliable.

 

I wonder what problems you are having,. . . I've had 3 aircraft using that engine, and so long as you look after it,. . . it SHOULD treat you kindly.

 

Welcome to the forum.

 

Phil

 

 

[Lucas Di Pentima]

Hi Idipenti,. . . . That's not a bad engine you've got there, . . . .I am sorry to hear that you are having problems with it. I've always found it to be a good powerplant,. . OK, it's only got single ignition, but it has plenty of power, and is usually fairly reliable.I wonder what problems you are having,. . . I've had 3 aircraft using that engine, and so long as you look after it,. . . it SHOULD treat you kindly.

 

Welcome to the forum.

 

Phil

Hey Phil,

 

I'm not the original owner of this engine, so I don't know how well it has been treated. Plus, I'm a newbie in this area and trying to learn as fast as I can for obvious reasons :)

 

My problem is that every 6 to 8 hours I've had some kind of power drop on the engine, and almost every time it has been solved by changing the plugs (I've had other problems, ie: carb spilling fuel that I solved by buying new jet needles, jets, etc).

 

I know that spark plugs shouldn't be changed so often, so I'm searching why this happens.

 

I've changed the double EGT gauge, the EGT probes and the RPM gauge so I can diagnose with some degree of accuracy what is happening. The data I'm seeing these days are the following:

 

* EGTs: 950F & 1000F (in different cylinders, at cruise) - At low throttle (4500 - 5000 rpm) on final approach, the EGT goes up a bit (approx a 50F rise)

 

* Water temp: 131F to 140F (55C-60C)

 

* Spark plugs (NGK B8ES) color: very dark brown, almost black. No carbon deposits and not oily.

 

* Sometimes hard to start

 

The point ignition has been installed as new about 5 flight hours ago.

 

The things I have to check/test are:

 

* Spark plug gapping: I've always installed them as they came in the box. I have to check if they're gapped as per the manual recommendations.

 

Also, when I bought this plane the plugs that came with it were the NGK B8EV (platinum electrode, as I understand), but as I can't find those plugs on my city and the Rotax manual say that they should be the B8ES, I thought that this is not the problem.

 

* Using higher octane gas: I've always used 95 RON gas, but I've read that pre-mixing it causes an octane drop.

 

* Covering part of the radiator to get higher water temps, I think the ideal should be around 158F (70C).

 

* Test if the RPM at full thottle get to 6800 as I used to have an old and uncalibrated RPM gauge until recently. Maybe the problem is with the prop pitch, if at full throttle the engine doesn't get to 6800 RPM, I should reduce the propeller's pitch. (and therefore, the engine load, that produces a drop in EGTs)

 

 

[Phil Perry]

Dear Lucas my friend,. . . .

 

I am truly sorry Sir, I have only just noticed your post. The forum restructure got me a little confused BUT, after a while, I GOT IT ! ! ! we are a bit stupid sometimes, us half English Half Australian people you know,. . . .!

 

Point number one, if you want your 532 engine to last more than a few weeks then I suggest you alter your propeller pitch to make it a little more COARSE,. . . . when I read that your RPM reading was 6,800, I nearly fell off my chair. You REALLY should NOT run that motor at MORE than 6350 RPM ABSOLUTE MAX. . . if you want it to continue working for any length of time. . . in my experience, most of our older Rotax users don't like them to run at much over 6,000 revs anyway, it reall shouldn't be neccessary with the correct prop for that type of aircraft / engine combination. !

 

If you HAVE to run such an rpm level, then buy another engine and run the 2 together at half power ( ! ) or make sure your passenger is not a fat bloke like ME ! ! ! I have used two of these engines for some time, and if you exceed 6350, then you will end up with damaged pistons, rapid ring wear / failure, and possibly damaged cylinders too, they are just NOT designed to run at such a high RPM whilst swinging a load such as a propeller. Some of the 2 stroke motorcylce engines I used in times gone by would rev to 15,000 rpm and sometimes a lot more,. . . .but after the race, they would be scrap metal. That's great to win racing prizes,. . . but no good if you want to use the engine again tomorrow OR. . . fly regularly, and SAFELY. Your plug gap for a Rotax 532 using the B8ES Plugs should be 18 thousanths of an inch nominal, and not more than 22 Thou.. I have not got a calculator nearby but I'm sure you can convert this to millimetric fractions. USING PLUGS STRAIGHT OUT OF THE BOX is just plain nonsense, all of mine are checked on receipt,. . . , I replace them every fifteen hours and every one has a different gap when recieved. . . . ( no offence intended). I do a lot of flying OVER LARGE EXPANSES OF SEA, so I try to ensure that I'm flying as safely as I possibly can. . . ( I HATE sharks. . .not many of those over in the UK, apart from those who sell microlight parts,. . . . )

 

I have no idea why you should get any unusual "Vibrations" after a few hours running, without more information, Is the PROP in balance, ? . . . .ARE YOU SURE ? ? ? I've found, using Rotax 377, 462, 503, 532, and 582 two stroke Rotax engines, and also some 440 Robin engines is that if they start to behave in an abnormal way, then it's probably because the mixture isn't right, the points gap is incorrect, OR. . . if you are using capacitive discharge / electronic ignition, then maybe you are overheating it ,?? (look at the EGT at all times, find out what the MAX EGT for the engine is,. in my experience, if you run a 532 engine and see an EGT of more than 1150 degrees F,. . . you are going to damage the engine. . . . BACK OFF, AND CLIMB MORE STEADILY. . . . forget the CHT, as if this redlines, it just means that this will simply tell you that you have stuffed the engine, by over-heating in hot ambient conditions, or over-revved it,a at the wrong plug gap setting, and / or the wrong fuel/oil mixture for far too long.

 

If your spark plug ends are black, whether they ar OILY or not, means that you are running a fuel/oil mixture which is too rich, so change your carb needle setting to lean the mixture ever so slightly.

 

The usual mixture for a happy 532 engine, is to mix 400 Ml of good quality pre-mix oil ( NOT INJECTOR OIL as this has a different viscosity rating )to 20 Litres of petrol, this may differ a little depending upon the kind of Automobile Gas you get from your local service station. . . I may be getting a little too OVER complicated here, but find out if you can, how much ETHANOL the gas contains, as, if there is too much of this in the fuel, and in the USA, it has been reported that in some states, they put as much as 37% Ethanol additive in their gas,. . . .

 

You will need to examine your fuel system very carefully, and very regularly. . . especially if you have any PLASTIC fuel hoses, and / or plastic fuel tanks with plastic output tube assemblies. . . as they degrade very quickly with high ethanol fuel content, and some other rubber type hoses will also start to degenerate internally also, thereby causing a problem with a build up of rubber and plastic bits which will cause blockages in your fuel filters.

 

After a while, you will find the right settings by making slight alterations to your fuel mixture. Ask your fuel hose supplier if the fuel hose you are using is OK to use with high ethanol content fuels, . . . if they don't know, then get on the web and ask the manufacturers of the product. !! This problem has caused all sorts of difficulties in the UK over tha past ten years. People just DON'T check. . . . Get onto Youtube and look for a video which is titled something like. . ." Problems with two stroke engines using ethanol additives in gasoline". . . It's a USA video made by a guy who repairs all sorts of 2 stroke machinery and boat engines,. . . it's most interesting and very informative.

 

And Remember, look for a nice TAWNY or light to medium Brown deposit on your plugs. But for heaven's sake, adjust the prop a bit to reduce that bloody RPM as soon as you can, or you'll be looking for another engine very soon.

 

Regarding your comments about coolant temperature 85 deg F should be the MAX remp to aim for.

 

I hope that you understand all of this, I am sorry that, although I speak a few languages, Argentinian / Spanish isn't one of them ( ! !)

 

Kind regards,

 

Phil

 

 

[facthunter]

You don't mention the oil you use. Use a specific two stroke oil. Pennzoil In the US have airtested and approved, one of their formulations. Some oil additives will short out plugs over a short time. A good 2 stroke oil doesn't lower the octane and don't use an old mix. Nev

 

 

[Phil Perry]

You don't mention the oil you use. Use a specific two stroke oil. Pennzoil In the US have airtested and approved, one of their formulations. Some oil additives will short out plugs over a short time. A good 2 stroke oil doesn't lower the octane and don't use an old mix. Nev

Silkolene Comp 2 semi-synthetic Premix Nev,. . . . The manufacturers stuck their heads on the block long ago and labelled it "Suitable for use in Aircraft" which none of the others would. I didn't mention it before, as it might not be available where Lucas flies, and there are so many others available. . .a lot of friends use Aeroshell and others, but I found the Silkolene worked for me and there is usually no need for decoking anywhere near as often either.

 

Phil

 

**Edited to add. . . **

 

I've used it in 2 stroke dirt bike engines over the years too, with no problems.

 

 

[Phil Perry]

Just a couple of additional bits I didn't mention,

 

Assuming you are not using a fixed pitch propeller of course. . . When checking the prop blade pitch angles, try to make sure they are all adjusted to the SAME ANGLE. ( Yes, I know,. . .this can be a bit of a pain to get right. . . ! ) you can see quite easily when ground running the engine at medium rpm ( Don't forget to tie the tail so something solid and have a competent person in the cockpit ! ! ! ) look at the propeller "Edge On" and you can see if the blades are "tracking" the same arc. If there appears to be a bit of a wobble, then one of them isn't set to the same pitch angle as the other and is leading or lagging in track. Even with a slight difference in pitch this can lead to peculiar vibrations at SOME RPM settings, these "Now it's there,. . .now it isn't. . ." type vibrations can often be mistaken for something else leading to some severe head scratching.

 

On coolant temperature, I should have added " 85 Deg. Max Temperature at normal cruise, you should be able to allow 90 - 95 degrees for very short periods of full throttle climbing, but limit this to no more than around 5 minutes, especially if you have a fairly high ambient temperature on the day. On one of my engines ( 582 bluetop oil injected twin ) I have a digital engine management monitoring system which is set to flag a large red warning lamp when the coolant temp exceeds 80 Deg.F *ALSO * I echo Nev's comment regarding the type of oil you use.

 

Phil

 

 

[Phil Perry]

Lucas. . . .

 

Oh BOLKOES. . . . . . SORRY ! I typed degrees "F" for Fahrenheit when discussing the coolant temperature, I HOPE you noticed that this is an obvious typo. . . ! This should of course have read DEGREES CENTIGRADE . . . not to be confused with Degrees F for EGT. . . . sometimes I confuse myself !

 

It was a SMALL amount of confusion which caused the British Mars Lander project to burn up in the Martian atmosphere a few years ago, when the technicians mixed up FEET per second with METRES per second velocity into the atmosphere. . . . so it got possibly THREE TIMES hotter than it should have done , unless speed versus friction is also LOGARITHMIC, rather than linear,. . . which means it would have been heated to many times more than it's design heatshield would survive. . . . . . ! ! ! ( I think I'll leave the mathematics to one of the Australian arithmetic technicians to work THAT one out. . . ) Although I'll bet it was a very pretty pyrotechnics display in the sky for the Martians though. . . .

 

Phil

 

 

[Lucas Di Pentima]

Hey Phil! thanks for all the posts, sorry I'm replying just now, that's because usually I'm away from the computer at weekends.

 

First, let me tell you that I got the typo, 20-something degrees C for the engine would be just too cold. :)

 

I'm having between 55 to 65 degrees C, I think that I should be getting at least 70 don't you think? Many on my airclub put some kind of paper of plastic to partially block the radiator. I think this is an awful solution and would like to know why I should be doing it if I don't live in a cold weather region.

 

The oil I've been using is ESSO Aquaglide outboard oil, because almost all pilots on my airclub use it (including the flying school). As I've said, many decisions I make are because someone with more exprience in the field has told me. This Aquaglide oil has been discontinued and now they have changed to some nationally produced oil that I'm not aware of its features, and I have a bottle or 2 of Aquaglide left.

 

I've been adviced on another thread to change to Castrol 2T red bottle, and luckily it seems to be available on my country.

 

About the plugs gapping: The 532 manual says that it should be 0.50mm (0.02 in), is that the maximum or the ideal value?

 

About RPMs: Until recently I've installed a faulty RPM gauge (it readings were higher than the true values), so I installed a new one and my only tests for the moment were on the ground: I got 6400rpm on full throttle. The manual says that the maximum recommended is 6800rpm (the same as the 582, am I right?) and I suppose that this kind of revs are to be used on full throttle on take offs only, is that a mistake? Why the 532 don't warn about not using the engine above 6350 RPM?

 

As far as I know, the prop pitch should be set testing the full throttle RPM: I have to get close to (but no more than) 6800rpm on the air, so maybe on the ground I should aim for 6600rpm at full throttle. This could explain why I'm getting low EGTs on cruise (no more than 1000F on one cylinder, and 950F on the other): I've read that if the prop has too much pitch, it will impose in the engine a higher load and this higher load produce lower EGTs (and higher CHTs, but those I cannot measure because I don't have the instrument), is this incorrect?

 

About the prop balance: I haven't detected vibrations but I'll take your advice if I change its pitch as both blades are indepent of each other.

 

About the plugs and carb setting: I'm getting somewhat black plugs but the carbs have the correct jets and needle as the manual describe, maybe the blackness on them are because I wasn't pre-gapping (newbie mistake, nobody told me and I didn't look at the manual... OUCH!) them until now?

 

About ethanol on fuel: In Argentina there's a law that says that the gas suppliers must add at least 5% of alcohol. I've checked this on the Argentinian's Shell website and there it says that their gas have between 5% and 10% of ethanol. I'm aware of the effects of ethanol on plastic fuel lines and tanks, my ultralight has a steel tank so I'm safe on that side.

 

Well, the message got a bit lengthy, thanks for you time and help :)

 

Best regards,

 

Lucas.

 

 

[Phil Perry]

Hey Phil! thanks for all the posts, sorry I'm replying just now, that's because usually I'm away from the computer at weekends.First, let me tell you that I got the typo, 20-something degrees C for the engine would be just too cold. :)

 

I'm having between 55 to 65 degrees C, I think that I should be getting at least 70 don't you think? Many on my airclub put some kind of paper of plastic to partially block the radiator. I think this is an awful solution and would like to know why I should be doing it if I don't live in a cold weather region.

 

The oil I've been using is ESSO Aquaglide outboard oil, because almost all pilots on my airclub use it (including the flying school). As I've said, many decisions I make are because someone with more exprience in the field has told me. This Aquaglide oil has been discontinued and now they have changed to some nationally produced oil that I'm not aware of its features, and I have a bottle or 2 of Aquaglide left.

 

I've been adviced on another thread to change to Castrol 2T red bottle, and luckily it seems to be available on my country.

 

About the plugs gapping: The 532 manual says that it should be 0.50mm (0.02 in), is that the maximum or the ideal value?

 

About RPMs: Until recently I've installed a faulty RPM gauge (it readings were higher than the true values), so I installed a new one and my only tests for the moment were on the ground: I got 6400rpm on full throttle. The manual says that the maximum recommended is 6800rpm (the same as the 582, am I right?) and I suppose that this kind of revs are to be used on full throttle on take offs only, is that a mistake? Why the 532 don't warn about not using the engine above 6350 RPM?

 

As far as I know, the prop pitch should be set testing the full throttle RPM: I have to get close to (but no more than) 6800rpm on the air, so maybe on the ground I should aim for 6600rpm at full throttle. This could explain why I'm getting low EGTs on cruise (no more than 1000F on one cylinder, and 950F on the other): I've read that if the prop has too much pitch, it will impose in the engine a higher load and this higher load produce lower EGTs (and higher CHTs, but those I cannot measure because I don't have the instrument), is this incorrect?

 

About the prop balance: I haven't detected vibrations but I'll take your advice if I change its pitch as both blades are indepent of each other.

 

About the plugs and carb setting: I'm getting somewhat black plugs but the carbs have the correct jets and needle as the manual describe, maybe the blackness on them are because I wasn't pre-gapping (newbie mistake, nobody told me and I didn't look at the manual... OUCH!) them until now?

 

About ethanol on fuel: In Argentina there's a law that says that the gas suppliers must add at least 5% of alcohol. I've checked this on the Argentinian's Shell website and there it says that their gas have between 5% and 10% of ethanol. I'm aware of the effects of ethanol on plastic fuel lines and tanks, my ultralight has a steel tank so I'm safe on that side.

 

Well, the message got a bit lengthy, thanks for you time and help :)

 

Best regards,

 

Lucas.

Hi Lucas, . . . . don't worry about LONG posts ( I do them all the time ad nauseum ! ) you might as well tell the whole story, as otherwise, responses and advice can be fragmented matey.

 

I'll try to address your questions sequentially. AND. . .I'm glad you were perceptive enough to notice my typo regarding the temperatures . . .! 1) Coolant Temperature. All engines love heat. . . they like to be run at the right nominal operating temps otherwise something will not work correctly, and you are right, . . . the temperatures you have quoted are TOO LOW. 55-65 degC is really NOT warm enough, and I can only assume that either your radiator is too large for the engine installation, and therefore will overcool the engine system,. . in which case you really WILL have to partially "BAFFLE" part of the radiator facing the airflow so that the coolant temperature rises to a more sensible figure. Operating at too low a coolant temp will not do the engine any good over time.Experiment with a small piece of thin plastic and partially cover the radiator core, then fly and check the results, adjusting as neccessary.

 

2) I have NO EXPERIENCE AT ALL with either Aquaglide nor Castrol 2T red,. . . just bear in mind what Neville ( Facthunter ) said regarding the fact that some oils can actually reduce the octane rating of the fuel you are using.

 

3) Plug gapping. . . the setting you have quoted is right in the middle of where it should be, BUT . . . . remember the ideal terminal colour,. mid brown NOT BLACK !!

 

4) The Rotax factory obviously want you to replace your engine as often as possible, and MY experience, backed up by my friend Ronnie Rotax ( Ron Bates Rotax, Stoke on Trent. . . who has just retired after some 30 years repairing and servicing these engines, IS that a manual reccommendation of 6800 RPM on a 532 is EXTREMELY OPTIMISTIC . . .and likely to cause the reduction in engine operating life and other problems I've already mentioned., Mainly due to the fact that, if you run an engine at extreme RPM, then other factors will determine the outcome,. . ie, if the mixture is not quite right, or one day you hve to use oil that isn't bang on correct,. . .you are running at the Extreme edge of the operating linits, and, unless everything else is absolutely OPTIMUM,. . . it will not take much to spoil your day. So give the engine a little leeway and operate it GENTLY.

 

5) Ron and I agree that your STATIC RPM, ie, that setting derived in a GROUND RUNNING TEST should not exceed around 6,150-6,200 RPM, you will never achieve full rpm in a static test anyway,. . ., but this should produce 6350 in the air. . . .if it does not,. . .then adjust the prop accordingly for a slightly FINER pitch angle setting. ok, ok, if this produces 6410 RPM, then THAT WILL DO ! ! ! ! HOWEVER. . . If you feel that you are simply NOT getting sufficient thrust from the propeller at these settings then it is possible that the size of the propeller is too small in diameter, or it has insuffficient overall "Twist / horizontal push or lift""It's only a couple of aerofoils after all. . . . to produce the required rpm at a given power setting. Thus far, you have not mentioned what the propeller specifications are, . . . and I am unfamiliar with the aircraft type / weight.

 

PLEASE don't confuse propeller BALANCE with TRACKING, as these are different issues. The popeller blade pitch angle is simply derived from an angle gauge. Whereas the BALANCE must be found by removing the prop, and sliding a Balance tool into the propeller boss ( the hole in it ! ) which consists of a tube closed at one end, this tube has a ridge on the bottom end rather like the rim on a shotgun cartridge. with a central hole, into which is passed a piece of cord or string, knotted at the bottom . It does not matter which way up you "Hang" the propeller itself, but the tube string must be at the bottom of the prop boss, so that you can see any imbalance where the string / cord exits the upper, or open end of the tube.

 

The propeller is then lifted off the floor or bench with the string and it is immediately obvious if the blades are not of equal mass, as the prop will tilt one way or the other, shown by the fact that the string / cord is not central in the tube. If you have a timber bladed Prop, then it is easy to correct a slight out of balance situation by spraying ( or brushing ) some clear varnish onto the lighter blade,. . . if however you are using a Composite, " Plastic" prop, then you may have to add a different amount of leading edge propeller tape to one of the blades to correct the imbalance. ( Or saw off a couple of mil with a hacksaw ! ! ! ! ! )

 

6) Ethanol / Alcohol additives to point of sale gas station fuel.

 

In the USA, they ALSO have Strict rules regarding ethanol additive percentage as well,. . . .don't believe it,. . . . look at the youtube vid I mentioned before, and you will see that in US service staitons, some oil companies /fuel distribution centres are not playing by the rules, and are adding a lot more ethanol than the current law stipulates. This can only mean that they possibly either, save money, or, don't really give a damn, as modern car engines can handle excess ethanol without difficulties, whereas a lot of older technology garden / industrial / generator / boat and even AIRCRAFT engines and fuel systems perhaps cannot.

 

You have mentioned that your fuel tank is stainless steel, This is good,. . . but be very sure about your fuel lines and filters . . . .It all boils down to a little care and commonsense.

 

Fly safely ( Please. . . ) I didn't,. . . I was just very lucky. . . . .

 

Phil

 

 

[farri]

Are there any ultralight pilots in this forums?

Hello Lucas,.

 

To your question! Yes there are and I`m one of them. I fly simply for the pleasure of flying! Started way back last mid eighties by building my own.

 

If you don`t already have it, here`s a link to an Ultralight site you might like http://www.ultralightnews.ca/

 

Cheers,

 

Frank.

 

 

[Lucas Di Pentima]

Hey Frank, thanks for the welcome! Sorry I didn't answer earlier.

 

 

[horsefeathers]

Hi Lucas,

 

I push this a bit, but I reckon this video has a lot of sense about running 2 strokes, from a guy who has seen more 2 strokes than most of us.

 

One of the things he pushes is to take the carbs and engine back to stock before trying to resolve the issue. Also got great info regarding rejetting (basically dont do it, as your problem is prob not due to carb jetting)

 

 

Cheers

 

Gerry

 

 

[Lucas Di Pentima]

Hey Gerry, thanks for the video! Actually, I've started my quest of knowledge about the 2 stroke engines by watching this video! And because I found it so useful, I bought their book about ultralight, but sadly there's not much more info about engines on it :(

 

Best regards

 

 

[facthunter]

Ethanol in itself won't be unsuitable for a two stroke BUT any ethanol content will require more fuel flow as ethanol requires less oxygen so your engine runs LEANER. If you are not sure how much ethanol, your problem is compounded. Ethanol also makes the engine run cooler.

 

Regarding the oil, Some use outboard because the engine (582) is liquid cooled. but Rotax specifically don't recommend oils for liquid cooled 2stroke engines for the 582 as the ring land temperature is the deciding factor. Any good quality 2 stroke engine oil would maintain the octane rating bar perhaps the "lawnmower" cheap types. Nev

 

 

[Lucas Di Pentima]

Ethanol in itself won't be unsuitable for a two stroke BUT any ethanol content will require more fuel flow as ethanol requires less oxygen so your engine runs LEANER. If you are not sure how much ethanol, your problem is compounded. Ethanol also makes the engine run cooler.Regarding the oil, Some use outboard because the engine (582) is liquid cooled. but Rotax specifically don't recommend oils for liquid cooled 2stroke engines for the 582 as the ring land temperature is the deciding factor. Any good quality 2 stroke engine oil would maintain the octane rating bar perhaps the "lawnmower" cheap types. Nev

Hi Nev!

 

When you say that the engine runs cooler with a high ethanol quantity, do you refer to the water temp, the EGT or CHT? I can measure the first two, and those are a bit low, what should I do to correct it?

 

 

[facthunter]

The evaporation causes it, so the engine case and body generally would be colder. (The carb can actually get covered in ice with higher concentrations of ethanol). The flame temps are probably not directly affected beyond the effect of the mixture being varied towards lean. To raise CHT most people tape over some of the radiator ( as Phil says).. Nev

 

 

[Lucas Di Pentima]

Hello all,

 

I've been told by an experienced ultralight pilot that he's using the Texaco Havoline TC-W3 2T oil, suitable for water and air cooled engines (it passes the API-TC standard also), I've searched the forum and cannot find any reference about this oil, do you have some kind of info about it? Here in Argentina is being imported from the USA.

 

Best regards