RysiuM

My Feedback: (1)

Welcome to the club


RysiuM

Ernie Misner

The XL series of engines is older than the new XLS series. That should explain the difference in spraybar or any other carb differences between the newer 40, 46, and 52 carbs.

Piston and liner problem cause a rich midrange??? That is doubtful.

Ernie

prgonzalez

Hi eveyone,

My good performer Magnum XLS-52A was broken in a crash. It is not an irony, it was a great engine for real after I fixed an air leak at the high speed needle. Now, this is the new story, I bought an used .52 to repair mine, but I ended repairing the used one. I flew it this weekend, and now I have the same UGLY FAT MIDRANGE. Now, what was perfect in the old .52 that is not good in this one?

I am using my old high speed needle. With this new carb, the engine takes about 30 sec to shutdown after closing the barrel. I will compare my old carb with this one to see what I can find.

Now, I am more interested in finding a cure for this great powerfull engine.

skukreja

My Feedback: (6)

has anyone tried teh tower hobbies carb with it?

Sachin

Ernie Misner

Most have the fat midrange (bad.... puts out the fire), and some don't. It makes me wonder if on the hot 52, if they finish up the porting by hand or something.

Ernie

backfire

Perhaps the induction timing and porting are on the edge; producing lots of power for a .52 but causing problems too.

RysiuM

My Feedback: (1)

I would agree with that. Blowing the mixture straight at the hot glow plug speeds up the flame in the combustion chamber creating extara power. I mean the power of 52 is avesome. This 1 lb engine makes the power/torque of much bigger and heavier engines available for other manufacturers.

Hawever the drawback is that the mixture must be almost perfect. The air/fuel doesn't have much time to mix with hot gases that helps mathanol to atomize and evaporate for easier burning. The fuel is directed straight to the glow plug. When tiny drops of methanol and oil touches the glow plug coil, before they ignite they evaporate taking the heat out of the glow plug coil. To much fuel at the time, and you have flame out. I think this may be the simple explanation what's going on inside this engine.

Solution to the problem (I'm always solution oriented) is to give the right fuel/air mixture. The ultimate solution (like my buddy did) is to add perry In-Flight Mixture Control (VP-IMC-05) - for 25 bucks it's much better solution than trying to replace the whole carb, that might work or not. And you can reuse it for other trouble engines too. Of course you need additional servo, spare channel in RX and computer radio to do it right.

If this is not an option, get spare low end needle (only 6 dollars or so), fine sand paper (like 600) and carefully shape the base end to lower diameter and less taper. Whatever you do (if you don't overdo it) it will be better than the original one anyway. It doesn't take much - only 0.1mm at the base. Put the needle on the press drill, Dremel or even turn it between fingers. The metal is very soft and easy to sand. Good caliper helps a lot but it is not a must. If you can build a model from the ARF, you can do the needle too.

Replacing the whole carb is expensive and in most cases will not work - this engine is quite unique and even if you find a carb that will fit without airleak, if may not mix the fuel the way 52 XLS wants.

Of course, the best would be if someone in Magnum just fix the needle design instead of taking engines in and mailing the new one out - this swapping game doesn't do anything. Even when customer service is great, it doesn't help if product sucks.

RysiuM

prgonzalez

RysiuM,

Could you draft a drawing of what you did so that we can understand the solution? I would like to understand how I should reshape the low-end needle to readjust the air-fuel mix.

Thanks
PRG

RysiuM

My Feedback: (1)

With accaent on the word 'draft'

The red part must be shaved out. At the base (near the threaded part) my needle was 1.34mm - now it is 1.25mm. At the tip my needle didn't change and is 0.95mm. Everything between was proportionaly removed. The idea is to change the taper (the thicknes change) to less diamteer change between tip and base. This will make less fuel delivered in the mid range (with the proper setup at the idle) and needle wouldn't open the jet as much while is traveling out with the barrel.

For good idle my needle is opened about 3/4 from the max at carb closed.

RysiuM

skukreja

My Feedback: (6)

very nice.. so, would you be willing to buy a few of these, "fix" them, and distribute them.. I don't have the tools to even try..

RysiuM

My Feedback: (1)

Why don't skip the middle man and let Global Hobby sell the 'good' needle. What they need is to get half of the stock to some local machine shop for grinding and put back for sale as a Magnum 52 XLS needle. Hello, Global Hobby !!! Anybody home??? [X(]

I bet you have. Here is how it can be done 'in your own kitchen'. Go to local automotive or hardware store and buy a wet type sand paper 600. One sheet is more than enough. Put it on flat hard surface (can be wood, metal, glass) and wet it. Now holding the needlle by the threaded part like you would want to turn it press the needle base against the sanding paper with the other hand (I mean finger). Nuw turn the needle like you would want to tune it. Don't sand the needle by moving it forth and back on the sanding paper. Just turn it otherwise you will mak a 'flat spot'. In a coule minutes you will be done.

Again, it's not a rocket science. As long as you don't overdo it and you don't make a 'flat spot' ypour needle will be better than the original one. Just remember you need to shave root part the most and try to not touch the tip. It goes easy as the needle material is very sft. It looks tough, but it sands easy like a pencil. Once you've done it you will find that the work is not even worth the shipping cost you would have to pay someone to do it.

First I thought that the needle is made with nano-milimiter precision. Big BS. I've seen roof nails better done than this.

RysiuM

grumpE

My Feedback: (6)

RysiuM,

Any flight time? Did it solve the issues in the air too? LHS is liquidating some special order stuff and I can get a pair for $55 each. Am up for the machining if it is worth it. Heck they are as cheap as an OS 40 LA at $55.

Eric

RysiuM

My Feedback: (1)

I will do this weekend. Man, I'm working whole day - I leave home, it's dark, I'm comming back, it's dark. I hate winters.

I hope to have very good flights this weekend with my CAP. The engine turnes 12500 rpm with APC 12.25x3.75 - it's over 8 lb of thrust. Not bad for 5.5 lb plane. The speed is also more than I need. That's why I had a dead stick - trimming the model in the air I had to back off from WOT, and after 20 seconds engine died. I hope to not have such excercises any more. I keep my fingers crossed. Anyway, I will report when I get back from flying field.


If I were you, I would buy all of them I mean, there is nothing wrong with the engine. When tuned well it runs awesome. It comes with 2 years warranty, so you can't go wrong with them. And Global Hobby has really great customer service. No questions asked.
For that price you can afford Perry Mixture Control. My buddy who does never fly slow loves this engine and when I see him flying, I know why. He does at least 5 flights a day and he never performed a dead stick. Actually he can dial the engine to the weather

When you start playing with the first engine I'm sure you will figure it out and the second engine will be a piece of cake for you.


RysiuM

RC-Captain

Tell ME about it.......... At least you don't have to worry about numbing fingers. That statement made my day . We are getting rain Saturday, so after working last weekend and not one flight I have to wait until Sunday. [&o]

I know I am beating a dead horse , but for a thread to get so many post something has to be wrong with this engine.

speedster 1919

My Feedback: (3)

Has anyone tried a perry non pump carb with good results. They have a small and large throat for just about any engine. $30 -40 seams like a better less complicated fix than an inflight adjustible pump. I have scored perry's on ebay for as little as $10.............

grumpE

My Feedback: (6)

Oops,

just read the times on your posts and realized you had mentioned no flying till the weekend. My bad.

Hey don't feel too bad. Four kids, two in Soccer, two in ballet, one in scouts and basketball. And changing jobs. Haven't flown since early September!!![:@]

I have almost finished an ARF I started in July

Eric

RysiuM

My Feedback: (1)

I got old ASP 60. This SOB never worked right. It could dead stick out of the blue. I put Perry carb on it as recomended solution. Nope. This SOB crashed my Supersportster 60 and now sits in the box.

I played with Perry Carb (the 60 size) a lot. I don't really see why it supposed to be better tan any simple spray bar or needle-jet type one. I mean it's not like Walbro. It still depends on fuel tank preasure and you can't adjust the fuel/air mixture in the entire range.

Good luck trying - maybe it will work with Magnum 52. But because this engine is very picky, I wouldn't be surprised, that it doesn't work.

RysiuM

RysiuM

My Feedback: (1)

Got this question on PM but I think it is very good question worth to answer in the formum so we all can benefit from that.

Are you sure this is a constant taper? If you have 1mm at the tip, and 1.25 at 2.5mm from the tip, the calculated diameter at the base at 5mm from the tip should be 1.5mm. 1.35mm would be 3.5mm from the tip. That means ether taper is not constant or the needle is flat from 3.5 - 5mm (good for you). Check measurements in many points just to verify the shape of your ASP needle.

The working length is from 1.25mm diameter to the end, - you measured it at 2.5mm. You can extend it by reducing the new base diameter to 1.24. The taper may be good at 1 - 1.5 degree.

But avoid the mistake (maybe not mistake, but my little problem) I did. I found that I could not screw the needle all the way to the end as the o-ring flange touched the barrel before the needle closed the jet. I had to take out the entire 0.5mm of flange to be able to use the full length of my needle. Is it good - probably not, but I had no other choice (barrel material is to hard for drilling).

So first set the barrel to fully closed position, then screw the needle in till it closes the jet. Now open the barrel to WOT and count how many additional turns you can screw the low-end needle in. One turn is 0.5mm. Add this distance to your 2.5mm from the tip and this is the point where your new diameter (1.25) should be. In example if you can add 2 turns, it is 1mm. So you can use 2.5mm + 1mm = 3.5mm of the needle (without removing the flange). Now recalculate the new shape of your needle:

Tip = 1mm
3.5 from the tip = 1.25mm
5mm from the tip = (calculated) is 1.35 (the same as before).

So you need to remove material from the mid part of the needle.

Do it slowly, and check measurements often - you will be removing just a little material from the needle and the metal is very soft.

Good luck.

RysiuM

RysiuM

My Feedback: (1)

Yes, I had 3 flights today with Kyosh CAP 40 (rebuilt) powered by Magnum 52XLS, Slimline pitts muffler (engine position horizontal exhaust side down). Prop APC 12.25x3.75. Plane is 6 lb total (including fuel). Fuel Wildcat 15%Nitro, 18% oil.

Flight 1. Still the sam Fox plug with idle bar. Low end tuned a little bit rich, hight end lean, mid range OK. I flew all throttle position and no problem, however after idling for 20-30 seconds when I hit the throttle WOT, there was a puff of white smoke. Transition however without any problems. Flying full throttle for a while and engine started to run uneven, eventually died. Deadstick landind without a problem. This CAP flies great, nothing like othe caps - doesn't snap, glides forever no tip stall tendency. Actually I like tis plane more, than the engine

Cause. I blew the glow plug. In the air high end was way to lean and blue head now is a little pinky. Remote glow adapter also melted a little. Definitly it was to hot.
I let it cool down, replaced the plug with what I had beforel (I don't remember what was it, K&B, Fox, OS-F - for sure not A3.

Flight 2. I leaned low end a little, but I couldn't open high end. Total 4 turns out and almost no change. Pinch test gives just a hair of rpm increase or none. I flew it anyway. All flying quite fine, however mid range got a little lean. I heard it was missing. I landed without waiting for dead stick.

I unscrewed back the low end. It helped a little on high end too.

FLight 3. Still a little lean on WOT. However no problem with running the engine in the air. I'm sure the needle does not have perfect shape, but much better than was before. I flew some fancy acrobatics however on vertical I could hear the engine leaned so I didn't push it to not blow the glow plug again. Landed without problems.

I think I lille overdid the shaping. The needle may need just a bit more taper. What I need is to measure if the low end needle is blocking the jet at WOT. I recalled it didn't but I need to verify it for sure. Maybe I have other problem with fuel delivery.

Conclusion:
After the mod engine runs much much better than with the original low end needle. Even running with the glow plug without idle bar engine neved died on me. It still not perfect but with a little more work on the needle and better tune up it will run great
.
I wish Magnum engineeres spend at least this much time as I did to design the best shape for low end needle for this engine. I mean, whatever I do, it will not be something that can be repeated for 'mass production'. It is just kind of home made fit and try.

For perfect running I still don't see the better option than perry inflight mixture control. If it is worth for you and possible from practical point of view, by all means go for it - the engine will reward you with awesome power and realiability. For sport flyers like me, a little experimenting doesn't hurt however.

One more, If I knew about all the problems the engine has, would I buy it? The price is quite OK for what you get. Two years ago I paid 99 dollars for it and I still don't regreat it. I just wish I knew about the problem and possible solutions earlier, so I wouldn't be so frustrated, and if I knew the solution then I would fly this engine for long time now.

RysiuM

freakingfast

My Feedback: (3)

Rysium, Looks like you got the 52 working at the field today. That's a lot less complicated then my servo controled remote Perry valve. C ya soon.

RysiuM

My Feedback: (1)

I see you found the thread. I like you call name BTW - kinda fits your style of flying

RysiuM

prgonzalez

All,

I re-shaped my low-end needle per RisyuM instructions. I did not go that far though. I do not have a precise caliper, but it definitely reduced the taper. At WOT, the needle is just in front of the jet. No gap visible from top view, but does not obstruct the outlet. Fuel: 10% omega 18% synthetic blend, Glow Plug: O.S. #8, Prop: APC 11x6. Wheather condition, cloudy. Temp. 68F.

I spend about 10 mins. adjusting both needles. At WOT I got a temp of 225-F after a minute. High-speed needle is open one full turn from fully closed. I started low-end needle at 1/2 out from fully closed. I had to close it about 1/4 of a turn. Transition was not bad in the ground. The engine had a hick-up about 1/3 throtle. I took off the plane and tested WOT vertical and level. No problems at all. I tried flying level at 1/4 throtle for a long period, no problems. Did some inverted flight, no problems. I ended dead stick and landed without problems. I ran out of fuel. I could not do a second flight because I was also flying two more airplanes. The only issue I still have is the engine does not quit even with barrel fully closed. Weird, I spend 30 mins with the carb and o-ring to make sure there was no leak.

So far, as RisyuM, I do not regret buying this engine.

RysiuM

My Feedback: (1)

Congratulation - another happy owner.

RysiuM

Robert Bauer

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I am sorry that I still feel the way I do. I feel that if a portion of the time spent trying to re engineer this engine was spent on proper tuning of the ORIGINAL carburetor ( Mainly the low speed needle ) you would all have good performance of a great engine. I have been told in the past that " I haven't seen enough of these engines yet ", " I was lucky getting a good one " and some comments not as polite, however I am sure that the three I own and the one a flying buddy has ( He also bought a second one ) were not luck, but proper tuning of the low speed needle. !! Yes it was a pain till I got to know what it needed. I am not going back again as to how to do it. Just check back through this thread, it is there. OK guys, you can once again flame my experience with these engines.

RysiuM

My Feedback: (1)

I see only three options:
1. you have different engine,
2. you have different ORIGINAL carburetor,
3. you don't care about mid range - then it's true, low and and high end can be tuner properly.

Whichever is true, I'm glad that you are happy with this engine, but don't imply, that you are the only owner of Magnum 52XLS who knows, how to tune the engine.

RysiuM