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Old Sep 09, 2007, 08:21 PM
Retired Army Aviator
Cyclic Hardover's Avatar
New Mexico
Joined Nov 2004
310 Posts
You will learn that the high speed needle is a no brainer. The losw speed is the root of all evil and where the fun is at. Thing to understand here is this. The place to check the adjustments you made on your engine IS NOT WHILE ITS IN THE AIR!

Even as a beginner, you can tune your engine better than most who have been doing it for years. You'll see who they are at any field. Thes know it alls are constantly fooling with their engines and blaming it on everything but themselves.

I am going to go over a couple scenarios here and you go with what fits.

Lets say you have a stick or a trainer where the engine is completely open?

Check you low end, when you get this right , you should not have to adjust it much at all in any given season.. Do this by letting the engine idle. Disconnect thfuel line or pinch it off completelywith pliers or hemostats.

Wait for the engine to quit. If the rpms increas as the engine quits, low end is to rich, therfore lean it maybe an 1/8 turn at a time. If the rpms just go down and quit, low end to lean. Open 1/8 turn at a time. Thisis very simple. I try and set mine for a slight increase.

Now the high end. If you get the high end too lean, tip the lane up in the air at full speed. if its to lean, the engine will probably quit. Usually you can find the ultimate lean spot and then richen it up a few clicks. I use the tipup method by dialing it to where I think its good. Then open the throttle wide ope and the rpms should increase when you tip the plane up.

Orrrrrrr. Have the engine wide open and do the pinch/release thing on the fuel line by the carb. many go for a quick increase in sound. Again, I look for no change to a slight increase.

All this stuff tells you that what you have adjusted has had an effect on the engine. Its talking to you just like a dog whining because he has to take a leak.

Learning to do this right the first time has an advantage. If something does go wrong, tuning is the very last thing I look for or mess with because i know my engines are perfect. I usually find the problem long before I get to that point.

Could be a bad plug, cracked line, loose stopper on the tank, clunk, this , that, whatever but not tuning.

And one more thing. Teflon on the low speed needle, Cmon now, Call up Hobby People and see if you can fix this, Your plane is now practically in the trash bag because of this stupidity, All its waiting on is a few flights to put it their. Your masking a problem that is still their. Low speed needles just don't come loose, they are generally very stiff. Fix it right.
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Last edited by Cyclic Hardover; Sep 09, 2007 at 08:28 PM.
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Old Sep 24, 2007, 07:44 PM
Registered User
United States, PA, Warminster
Joined Dec 2006
158 Posts
I flew my 46 XLS yesterday. Three flights, three dead sticks. I and my club's engine gurus have been fooling with this engine for 3 years. Most of my flights have ended in dead sticks. You get what you pay for.
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Old Sep 24, 2007, 08:37 PM
Retired Army Aviator
Cyclic Hardover's Avatar
New Mexico
Joined Nov 2004
310 Posts
Quote:
Originally Posted by Alebartz
After I applied teflon on the threads, I set the LSN to the factory settings as described on the user's manuel. It says while keeping the barrel on the full throttle, screw the LSN clockwise until it stops and then loosen it counterclockwise 2.5 turns. I did exactly the same.

I wonder the factory setting is changed just because I applied some teflon on the threads?? If it is the case, then I guess the factory setting should be more than 2.5 turns, right?
Factory settings do not mean a thing. Forget they exist because you will go nowhere. Factory settings do not take into account where you live in the world. They mean nothing at 5000ft where I live or many other climates of altitude, temp, humidity and the rest of it. You need to learn to get your own "factory setting as to where you live and this is exactly how to get it.

Must be done in this order.

Set your throttle barrel opening to an approximate idle position (this is not much)

Next close your low end and open the high end about 3 turns.

Attach a fuel line to the carb nipple long enough to blow into.

Now at the same time, open the low end and blow into the tube until you hear a hissing noise. When you do, stop---this is your factory setting and should be good enough to get you started up and adjust from their.


IN answer to your other post about tuning you can tune your engine perfectly. Anybody can do this but most don't.

The high end is generally a no brainer most of the time. The pain is the low end. Very basic 1st grade level stuff here.

Tune the engine to where you "think" you have it right. Let the engine idle. Now either remove the fuel line from the carb or pinch it and wait for the engine to quit.

LISTEN TO THE RPMS AS THE ENGINE QUITS!!!!!!!

If the rpms increase as the engine quits, low end to rich, if the rpms just decrease and quit, low end too lean. I usually adjust my low end so I get a very slight increase.

Now each time you adjust the low end, you need to readjust the high to bring it all together. it's such a simple thing. Good luck.
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Last edited by Cyclic Hardover; Sep 24, 2007 at 08:51 PM.
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Old Sep 25, 2007, 10:50 AM
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ivanc's Avatar
United States, TX, Round Rock
Joined Dec 2004
9,656 Posts
Have you tried replacing the fuel tubing in the tank and between the tank and engine? Have you replaced the tank? Have you moved the engine to a different plane with a different tank setup? Very often tuning issues are caused by bad plumbing or improper tank setup.

Ivan
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Old Sep 25, 2007, 11:34 AM
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windsor,ontario,canada
Joined Jun 2001
473 Posts
Quote:
Originally Posted by JPMacG
I flew my 46 XLS yesterday. Three flights, three dead sticks. I and my club's engine gurus have been fooling with this engine for 3 years. Most of my flights have ended in dead sticks. You get what you pay for.
My son and I have 3 46XLS engines that run great. They never dead stick(unless out of fuel). It sounds like you may have an air leak somewere around the carb. All three of ours have great power and many,many flights. Best deal around I think I bought them on a sale for $49.99 each.
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Old Sep 25, 2007, 01:11 PM
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United States, PA, Warminster
Joined Dec 2006
158 Posts
Yes, I suspect it is an air leak. The tank and tubing are not the problem. I have inspected and replaced them multiple times. I have sealed the carb and back plate, Teflon taped the needle. I can reproduce the problem on a test stand as well, so it is not specific to the airplane. I suspect the leak may be caused by the fit of the crank shaft into housing (too much clearance). Another possiblity, I'm told, is that there is a tiny weep hole between the front bearing and the case, and this may be oversized.

I realize many others have good luck with the 46XLS. Apparently I got a bad apple. Actually two bad apples, the one I now have is a warrantee replacement for the first one, which wouldn't run either.

Sorry for hijacking the thread. Thanks for letting me vent. I feel better now.
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Old Sep 26, 2007, 09:20 AM
Registered User
Spring TX
Joined Feb 2007
123 Posts
Mine seems to need a little hotter glow plug. It would dead stick quite often on Fox RC longs. It was better on OS 8's and never dies on A3's. I had to fix my low speed needle as well. Dinged the threads just slightly and no more probs since. It has been a great engine since all the bugs were worked out.
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Old Sep 27, 2007, 12:03 PM
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United States, PA, Warminster
Joined Dec 2006
158 Posts
I'm running an Enya 3, which is a hot plug. I'm using 5% nitro 10% synthetic 10% castor fuel. This combination works well in my OS, Thunder Tiger and Enya non-ringed two strokes. I have not experimented with other plugs or fuels on the Magnum.

I am fairly sure my problem is an air leak because the high speed mixture is unstable. I have substituted an OS carb for the Magnum and the problem persists. So I believe the air leak is through the block, either at through the front bearing or the weep hole. I have sealed the back plate thoroughly with high temp RTV.

I am running the Magnum muffler that came with the engine. Could this be a problem?
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Old Sep 28, 2009, 02:13 AM
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Joined Apr 2007
34 Posts
Hi, I have messed up with my Magnum .46 XLS LSN, and I want to bring it back to the factory setting. I applied as the manual, "open the barrel completely, close the needle, open it 2.5 turns" but then I cannot close the barrel, it stucks, the needle does not let the barrel close. Am I doing something wrong?
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Old Sep 28, 2009, 12:20 PM
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ivanc's Avatar
United States, TX, Round Rock
Joined Dec 2004
9,656 Posts
Have the needle end (with the slot for adjusting) flush with the barrel. This will get you close to the initial setting.

Ivan
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Old Sep 29, 2009, 12:35 AM
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Joined Apr 2007
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that didnt work
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Old Sep 29, 2009, 03:28 AM
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turk1's Avatar
Istanbul, Turkey
Joined Aug 2004
847 Posts
You are using wrong needle.İt should be the long, sidemounted,horizontal needle,not the overcarb.needle with spring.
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Old Sep 29, 2009, 04:19 AM
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Joined Apr 2007
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thats the needle i am adjusting (inside the throttle arm, not the rotor bolt).
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Old Sep 29, 2009, 12:59 PM
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ivanc's Avatar
United States, TX, Round Rock
Joined Dec 2004
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Quote:
Originally Posted by ccure83
that didnt work
In what way exactly it did not work? Could you close the throttle barrel? Were you able to run the engine and if so how did it run?

Ivan
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Old Sep 29, 2009, 06:38 PM
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Ca. USA
Joined Sep 2008
156 Posts
You can crack the barrel open very slightly, close high speed needle, and blow through a fuel line attached to the fuel inlet. Open low speed mix until you just hear a hiss....that should get you near the mark.
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