LOL... yes I sent mine in. They very promptly replaced it with a brand new engine..... which wouldn't run consistently either. I know you are all going to say that it was something that I was doing wrong. I wasted half a flying season messing with those two engines and had all the experts at my field helping. At some point you say to yourself this is stupid and just move on, which is what I did.

I have had zero problems with my Enya, OS, Saito and Thunder Tiger engines in 10 years of flying.

BTW, mine were 46XLS engines.

It was bought direct from a shop here in spain by me.
It has only about 4-5 months usage.

Why should I change the glow driver after run-in?

Today, the other man looking at my engine has been a world champion acrobatics pilot one year and a spanish champion many other years.... he is apparently known as "mr motors"
He was starting to get confused as he would find one problem "fix it" and another would appear... Unfortunatelly he had to leave before finnishing.


The assembly at the rear hasnt been removed because I couldnt be bothered removing it as it makes no difference to the plane it being there.........


Truthfully i'm starting to think... "oooooosssssssss! ooooooooossssssssssssssssssssss! oooooooooooooooooooooooooossssssssssssssssssssssss sssss!" (long drawn out haunting, dream style sound) Mostly because its more common, its more reliable and the other guys at the club all have them, IE they can help me out more as they "know" the engines better.
plus moving from something that was €50 to €150, where the money is worth it, isnt a bad idea to me!

[quote]ORIGINAL: JPMacG

Some Magnum engines do have problems. You will do well with an O.S.

Boy that was an open ended statement.
I run all Magnums ranging from 1.20 4 strokers in a KMP OV-10, to 2 .61's 2 stoke in a Cessna 310, and 2 .91's 2 stroke in a Black Widow, and a .91 4 stroke in a Byron Bonanza. In multis you must have total reliability or you scratch one airplane. I've had one engine out with the Widow due to the muffler coming loose. That's it. These aircraft are flying for two years and counting. For the money they are a great value.

They are a great value if they run. If you get a dog they are a terrible value and a huge waste of time.

The impression I get, is that for someone who knows more about engines and LIKES to "tinker" with them.. they are great...

For someone like me who preffers less work load and, due to work, has little time to spare on maintenece, brands like OS are more suitable....
Maybe thats what you pay for when you pay less.... rather than a "better engine"

Anywho, I have it all plumbed in again, and had a wee test run at home, got the GF to man the throttle and I shook the hell out of this thing, turned it every way I could the lot...
after setting the needle valve... no hickups, no stutters, nothing.

Tomorrow i'll take it to the club and see what I get out of it....

The Magnum XLS .52A two stroke is an outstanding engine. I also removed my remote needle valve setup during initial break-in when I saw it was prone to leaking air. 10% nitro is plenty for the Magnum XLS .52A, although they seem to prefer a hot plug (O.S. A3, Enya #3) when running lower nitro.

Trying to insulate the tank from vibration by surrounding it with foam would be a good basic step toward reducing inconsistent runs. The XLS .52A is a very powerful engine and it certainly could foam up your fuel tank if run with an out-of-balance prop or spinner. Also, I've found that 11x7 two blade props weren't too much of a load on my XLS .52A. I've flown it extensively with 11x7 two blade and 10x7 three blade props.

Magnum engines use a true chrome sleeve and will require a longer break-in period than some other two strokes before the idle settles in. After four months of running, however, I'd expect the XLS .52A to be good to go. Mine seemed to settle in nicely after about eight or so tanks of fuel.

Everyone seems to be ignoring ceecrb1's comments about fuel leaking out of the front of the engine and messing up the inside of the cowl. This could be indicative of:

A) Fuel spitting out of the carburetor due to an overly rich low range, mid range, or high needle setting
B) Fuel spitting out of the front bearing
C) Fuel leaking out of a crack in the crank case
D) Fuel leaking out of an imperfect cylinder head gasket seal
E) Fuel leaking out of a worn, cracked, or split carburetor o-ring
F) Fuel leaking out of a loose or broken carburetor-to-crank case mounting

I would recommend pulling the engine out of the plane in question and running it on a test stand to see if you can determine the source of the leaking fuel at the front of the engine. This would go a long way toward isolating the source of the problem so the engine can be properly repaired.

Put it on a test stand with a fresh, hot long plug and some fresh fuel. Use a balanced prop, perhaps one with a slightly lower load like an 11x5, for bench testing as the engine won't get as much air on the ground for cooling as it does in flight.

If there is no obvious fuel leak from the front of the engine on the ground, and the engine tunes well and idles and transitions reliably on the test stand, then your engine problem likely isn't directly attributable to your engine. If the tank outlet and carburetor intake aren't the same height, the plane will more easily richen or lean out at various angles while in flight.

The forums are littered with requests for help from folks having problems with O.S. Max engines, the difference is folks usually don't recommend shelving the O.S. engine in favor of another two stroke. Work through this problem and you'll not only be rewarded with a great running and reliable Magnum XLS .52A, but you'll gain a lot of general knowledge about engine set up and tuning that will help you in the future regardless of whatever brand of engine you're running.

I may have missed it, but make sure the carb to crank O ring is not nicked and is compressed well.

As stated before, the Mag mix needle can be a source of porblems. I have had to replace two because the O-ring grove was cut to deep and there was no compression of the O ring. If this is the case, the mix needle will be very easy to turn.

A tip one of our guys gave me was to smear petrolimum jelly around both needles an if you are leaking air into one or both it will be a tempory fix, lasting long enough for a flight to see if that is the problem.

You mentioned a cowl. You need to make sure you are getting good airflow around the engine. You need an exit opening about twice the area of the inlet opening. I would fly it several times with the cowl off and see how it preforms. Restricted air over the engine will cause it to overheat in flight and start giving you fits.

Some spray out of a carb is to be expected. Even on the four strokes. You can put a stack on the carb giving about 3/8" additional length to the spray bar that will greatly reduce the amount of fuel spit back out. I would also make sure your back plate has a good gasket and is tight. Whacking the needle valve mounted on the rear will sometimes crack the back plate.

Tune the engine with a tach. Find peak RPM and then back off about 300 to 400 RPM. Adjust the top end, then adjust the idle mix. Re adjust the top end again, and then back to the idle mix. Getting them right is a balancing act as there is an interaction between the needles and changing one effects the other. About two to three times through the sequence and you will have them balanced.

Don

I KNOW the source of the fuel leak. It is between the large nut for gripping the prop, and the bearings behind it.

I'd like to know more about this..
The engine has always done this but recently is a LOT worse.
At first I noticed the dirt inside the cowel after a months flying, now its after a days flying. I'm starting to wonder if the engine is heating up, expanding and loosing compression through there..... or something along those lines.

check back on the photo, you can see the bearings and a blue seal.. it comes from there.. but exactly which part of "there" I cannot say.

This cowel is REALLY dirty, like soaked, after yesterdays flying alone, which was about 5mins in the air and a total of 7-8ish mins run time on the ground.

The front seal on a two stroke glow engine is made between the crankshaft and the crankcase, not the bearing as most people think, it could be that either the crank or case is out of tolerance causing the fuel to leak out, but most of the time a leak here will create an engine that won't turn off as it is drawing air in. Under normal circumstances there should be a vacuum present there as the engine is "sucking" the fuel mixture from the carb, could it be possible there is something blocking your exhaust causing some internal pressure in your engine ? or maybe the piston is scored and blowing pressure inside your engine.

Also does the fuel leak out as it's running? if it is just when you are starting the engine you maybe heavily over priming it.

Also back to the head question, has anyone seen a Magnum .52XLS with the head he has on or have they all been the blue head. I think this engine may have been modified.

I think its more likely it could be a chinease knock-off rather than modified..
I bought it directly from a shop.
A shop witch no-longer exists.

HOWEVER. Today was the first successfull "complete" flight in a long time. Ie I chose the landing time, it wasnt dictated by a dead-stick or a "nasty sounding engine".

Truth is it only flew once as I am converting over to my new Phoenix Dolphin 40.... Much more fun!

Fly RC engine writer Andrew Coholic pretty much summed up why so many people have problems with new engines and that proper break in and tuning with a tach is so important before flying http://www.rccanada.ca/rccforum/showthread.php?t=79434

A very interesting read.

But 0 facts or explanations.

and Yes, My engine WAS run in. to the letter of the manual.

Sounds like you're replumbing fixed the problems. My best guess is that you had a pinhole leak in one of your lines, probably inside the fuel tank. That would explain why the engine would lean out and starve when you shook the plane around (flexing the klunk line introducing air. It would also explain why the plane would be fine on the ground but die in the air. Vibration and motion of the plane throwing the klunk around, introducing air, leaning out the engine in flight, subsequent heating up of the cylinder, and loss of compression. If the engine is running now, keep flying and have fun.

As for the leak around the front bearing, its supposed to leak. During the stroke there will be a short period of time when there is sufficient pressure in the crank case to force oil and fuel out through the front bearing. This is essential to lubricate the front bearing. The seal on the bearing is to keep dirt out, not fuel in. That seal could be a little looser than normal, but still be within tolerance, and that will cause more fuel to come through.

If the fuel and residue on the inside of the cowl are black, its another sign of the engine being too lean. Hopefully fixing the tank will reduce this. The oil on the side of the plane should be clear, or slightly colored at the worst. Black inside the cowl could also be a sign of vibration induced metal wear. Check your exhaust bolts to ensure they're tight. Also make sure head bolts are tight.

Brad

Brad

OK next question.

I read in a post yesterday someone asking if i'd changed the glow driver after running in...

Should I do this and if so, why???

Sometimes the glow plugs (not driver) get fouled by small metal particles that come loose during break in. If a new engine is running poorly, sometimes it helps to put a new plug in. As previously mentioned, go with a hot plug (OS A3).

bRAD

Well I feel bad for the CEECRB with the magnum. However, I will have to disagree with everyone who has bashed this engine. I have OS and Super Tigre engines and I prefer the Magnum engines hands down. I have actually switched all of my engines out and am running all Magnum engines. I have the 46, 52 and 91. That being said I have only messed with the 2 strokes, I know nothing about their 4 strokes.

As far as the simplicity of breaking this engine in and getting it set right was as simple as doing the initial break in as written in the directions. I have never touched the low end on these engines. I have only adjusted the high end adjustments and use my trusty tach. After my break in I only have to touch the high end because of the humidity/temperature. I also use OS 8 glow plugs with all the engines. I absolutely swear by these engines.

I had a magnum 52 once. This engine had phenomenal speed and power. Unfortuneatly I could never get it to run for a complete flight unless I ran it so rich that the glow plug lasted about 3 or four flight before it became useless. this engine would be running at 3/4 throttle and it would just go dead in mid flight. A year and a half later and sending it back for repair yielded no joy. When someone offered me a buck for it I happily took him up on it. He got it too fly for at least two flights but I haven't seen the engine in 2 years since that day. Even I could get it to run for a few flights but it would kill the plug.

It's possible that his engine has a different head because it is sold in Spain and may be a slightly different offering than sold elsewhere. Perhaps a different compression ratio if FAI fuel is predominant in that area. I don't know, just throwing out ideas.

I also noticed this with one of my 46XLS engines. I tried replacing the stock front bearing with a sealed bearing. The sealed bearing may or may not have reduced the fuel leak - I'm not sure - but the engine did not run any better with the sealed bearing.

As I understand it, the front seal is accomplished by the slip-fit clearance between the crank and the engine case, not by the front bearing. So a sealed front bearing is not necessary, however, if the clearance between crank diameter and case bore is too large a sealed front bearing might help.

I also understand there is a small weep hole between the crank area of the engine case to the front bearing. The purpose of the hole is to provide lubrication to the bearing(?). I have heard that if this hole is over sized there could be problems with air leaks and leaking fuel. For lack of a better idea, I believe this may be the problem with my engines. I have eliminated just about everything else.

I was going to say the same thing!

Problems where the engine seems to run fine on the ground but not once airborn tend to point to either tuning issues, or plumbing/pressurization problems.

Hi!
The Magnum .52 is a fine engine no doubt about it!
Some questions.

Here is what I would if I were you.
Fuel: I would run 20% castor oil and 5% nitro and the rest methanol...I mix my own fuel like many do over here in Sweden.

Tank: When I use ordinary R/C tanks I use the Uni-flow principle with 2 clunk tanks. Not necessary... but a little better than a one clunk set up. Tettra "bubbleless" isthe best tank...but of course not necessary!

Engine and tank : Magnum .52 is a very good engine but like all engines it has to be mounted right to function well. Always follow the old rule that say: -Mount the tank so that a the carb intake orifice is in-line with the center of the tank when the airplane sits horizontal. This is very, very important!!!

Engine: Mounting the fuel valve to carb helps in having a good engine set up. Check head shims. If it has two shims and you run just 0-5% nitro ...remove one of the head shims.

Glow plug: OS 8, Enya 3 or 4 or Nova -Rossi or Rossi 3 or 4.

Prop: There are many that work...like 9x8, 11x6, 11x7 11,5x6 APC , 12x4, 12x5, 13x4 and so on. Some good props are APC ,Bolly, Graupner "Cam-prop" and RAM. See too that you balance them.

No it's not... this is so overstated here...

It only affects siphoning, rarely does it ever affect a small engine under normal flight conditions... we would be having deadsticks each time we pointed the nose up otherwise.

Mine does the same on a test stand as it does in the air. It will not hold a steady high end mixture. I have swapped carbs/needles with known good carb/needles, swapped fuel systems, RTVed the back plate, RTVed the carb, Teflon taped the needle, tried a sealed front bearing, replaced glow plugs, retorqued the head, run different fuel, experimented with tank size and height, etc, etc ad nauseam.

No big deal really, these engines are cheap enough that I can accept a lemon now and then. My previous comments were intended to help the OP, not to diss Magnum engines. I'm sure that other manufacturer's are not perfect either.