|
Problem problem problem
Guys,
i recently bought a used OS 40LA, and today i fired it up. I used an APC 11x6 prop, 10% N Cool power fuel. My problem is that when i put my airplane vertical by hand to try and see if the engine stalls, it actually did. No matter how much i opened the high speed needle valve, from 2 turns to 3-1/2 from fully closed. Also, the engine came without the needle holder, but because i wanted to try it TODAY :) i glued a piece of wood on the firewall and installed the needle valve there,with a self taping srew. Also, i saw that the needle valve is approximately 5 fingers higher than the carb position. Does that affect the engine? Last, idle is perfect,also the WOT and transition. But when i grab the ARF and put it in vertical position, it runs and then stalls.[:@] |
RE: Problem problem problem
do you have your fuel tank hooked up to the pressure tap on the muffler.
|
RE: Problem problem problem
In my experiences a 11x6 prop may be too big for the engine. I run a 10x6 prop on them Ok.
You might be loading it down too much. The engines are not a powerhouse. They were designed as a entry level engine that is easy to use and run. if the prop is too large, it loads the engine down a lot, and the engine doesn't draw fuel at the lower RPMs very well. Did you hook up the muffler and run the fuel tank vent tube to the vent fitting on the muffler? A little muffler pressure is good for the fuel draw. Sometimes the fitting has the hole in it blocked, it's worth it to poke a paper clip end or something down it to see if it is blocked or not and clear it out. Also try to keep the fuel lines going to the carb as short as possible. You don't see any air bubbles in the fuel lines do you? Especially the short fuel line from the remote needle to the carb. What size fuel tubing are you using? Small, medium, large or extra large. I think medium is the one to use on the engine. |
RE: Problem problem problem
prop is too large for a new LA engine. A 10x6 is plenty prop for any .40, especialy when running in.
|
RE: Problem problem problem
ORIGINAL: dalolyn do you have your fuel tank hooked up to the pressure tap on the muffler. the engine is used,not new, and according to the owner it is also run in. Using the APC 11x6 i get a good "slow" idle, even at full throttle, with the nose at the usual position,engine works fine, Only problem is when i put the plane verical. I have the 3-line setup on the fuel tank. One for filling, one for the muffler, one for the needle valve[:o] |
RE: Problem problem problem
Hopefully you have the filling one plugged when you are running the engine. If you don't the one to the muffler isn't doing you any good.
Denis |
RE: Problem problem problem
Many variables can cause the problem the problem you have: WOT set too lean; fuel tank position too high; wrong heat range glow plug; insufficient muffler pressure to fuel tank.
Set WOT with a slow pinch test on the fuel line. If set correctly, you should hear a slight increase in RPM's. If set too rich, you will hear a larger RPM increase. If set too lean, you will get a drop in RPM or the engine will die. Tank position: the centerline of the tank should between in line with the spraybar to 10mm below it. Your positioning of your needle valve should not have an effect. Commonly, people run into the problem of a too high tank if they mount their motor sideways or inverted on an airframe designed for an upright engine and not reposition the tank. As for the glow plug, you need a hot heat range plug like the OS #8. A colder plug can give you "flame outs" and not show it on the ground. Check the pressure nipple on the muffler for plugging or constriction and your tubing for a leak. Well used mufflers will get a buildup of varnish or gunk. Remove the nipple, clean off the face and run a drill or wire through it to clean out the hole. Other than that, my only other recommendation is change your propeller to a 10x5 or 10x6. An 11x6 is too much load for that motor. |
RE: Problem problem problem
Way to big a prop for a LA40. If it goes lean it could be overheating and stopping. My son's trainer has a 10x6 on one and has a low idle. On a ww1 fokker D8 I ran an FP40 with an 11x4. That prop needs to be on a .46AX.
|
RE: Problem problem problem
I agree with all that has been said; all those variables apply. What strikes me is you said the needle valve is 5 fingers above the carb. Does your fuel have to travel uphill 4"? Seems quite a big distance.
|
RE: Problem problem problem
One more thing that you should check is to make sure the clunk is not up against the back of the tank. If it is against the back of the tank it can shut off the fuel real quick. I try to set mine with 3/8 inch clearance.
I agree that an 11x6 is too large for a 40LA. Fred |
RE: Problem problem problem
Kostas, I agree with some of the others: the 11 x 6 APC prop is a bit too much for the poor old .40 LA. An MA 11 x 6 would be a better bet (1bout another 1000 rpm), or maybe an MA 11 x 5 or an APC 11 x 4. Depending on the airframe, an APC 10 x 6 might work too.
It's unlikely to be doing more than about 9 and a half to 10 grand with the APC 11 x 6, which will badly hurt fuel draw. |
RE: Problem problem problem
ORIGINAL: huck1199 I agree with all that has been said; all those variables apply. What strikes me is you said the needle valve is 5 fingers above the carb. Does your fuel have to travel uphill 4''? Seems quite a big distance. Guys here are some pics to see exactly how my setup is. It's kinda weird the engine to run excellent on idle,WOT and midrange+transition and not run good once vertical....d@mn it's frustrating.[:@] http://img687.imageshack.us/i/hinges001.jpg/ http://img340.imageshack.us/i/hinges003.jpg/ http://img503.imageshack.us/i/hinges004.jpg/ And my other loves airplanes...:D http://img260.imageshack.us/i/hinges006.jpg/ http://img510.imageshack.us/i/hinges007.jpg/ |
RE: Problem problem problem
Kostas, give that poor engine a break! A 11x6 is too much prop. Your .40la has the power of a .25BB engine, maybe. I have found that a 10X5 is a very good prop for the .40la. As for your problem with the fuel draw, do you have the tank placed close to the engine? If not, maybe the engine can't pull the fuel that far when the plane is held vertical. |
RE: Problem problem problem
As nearly everyone else has said, the 11X6 is too much prop for a normal 40 and the LA is a little weaker than that so it's definately too much prop so start with changing that to a 10 X 5-no more than 10 X 6 for sure! As for this being a "wierd" problem, there's nothing wierd about it really as this is exactly why you hold a plane vertical. You are looking to see if you have this problem. It is likely that you need to richen the high speed needle a few clicks even if it means giving up a couple hundred rpm when level so that when vertical it won't lean out so much and quit. THAT condition will ruin an engine in short order if you routinely fly it that lean.
|
RE: Problem problem problem
Kostas, when you use too large of a prop the airflow velocity through the carb is too slow reducing fuel draw. Also, where is the airbleed screw set, it should be about halfway across the inlet hole or slighly more closed.
|
RE: Problem problem problem
I think your fuel line slipped off inside the tank. To test for this, just put a little fuel in and try to run it. No go? Than that's it.
|
RE: Problem problem problem
It's not all that weird, until you systematically try the good suggestions given and start eliminating variables. Then, if you still have a problem it is weird. And FF's tank suggestion would sure as heck do this. So would, depending how things are positioned inside the tank, reversing the fuel and vent lines.
MJD |
RE: Problem problem problem
Change to a 10x6 APC prop, take out cone inside muffler, take off any exhaust extensions, shorten fuel lines as short as possible - these all bog down your engine and make it run hot and lean - then run slightly rich till broken in -
|
RE: Problem problem problem
ORIGINAL: Hobbsy Kostas, when you use too large of a prop the airflow velocity through the carb is too slow reducing fuel draw. Also, where is the airbleed screw set, it should be about halfway across the inlet hole or slighly more closed. Hobbsy, thank you for your suggestion, but mY English didn't help me understand what exactly you meant....[:o] Today , i checked that the correct line goes to the correct place, and the tank's position cann't change because there isn't any space inside the fuse to move it,lower it or place it higher. I believe that it's in the correct orrientation with the carb center line! |
RE: Problem problem problem
Hobbsy is telling you that your engine is not turning fast enough with the large prop, and this is causing poor fuel draw through the carburetor. |
RE: Problem problem problem
Like they all stated the 11x6 is too big of a prop, try a 10x6 or evena 10x5. If your Extra is designed for slow flight a 11x4 prop mightwork Ok for you.
In looking at your pics, it looks ok, except the remote needle valveshould be lower and inline with the carb. When you look at the factorysetup, you will see the remote needle valve inline with the carb andmounted to the top two screws of the rear crankcase cover. now it is possible the fuel line inside the fuel tank has a problem.But if the engine is running Ok until you point the nose up, then youhave a fuel draw problem. The first thing then is to go to a smallerprop and get the RPMs up so the fuel draw is improved. Then check themuffler vent fitting for the fuel tank, it may be partially obstructedor blocked off. |
RE: Problem problem problem
ORIGINAL: earlwb Like they all stated the 11x6 is too big of a prop, try a 10x6 or evena 10x5. If your Extra is designed for slow flight a 11x4 prop mightwork Ok for you. In looking at your pics, it looks ok, except the remote needle valveshould be lower and inline with the carb. When you look at the factorysetup, you will see the remote needle valve inline with the carb andmounted to the top two screws of the rear crankcase cover. now it is possible the fuel line inside the fuel tank has a problem.But if the engine is running Ok until you point the nose up, then youhave a fuel draw problem. The first thing then is to go to a smallerprop and get the RPMs up so the fuel draw is improved. Then check themuffler vent fitting for the fuel tank, it may be partially obstructedor blocked off. Ok guys, i will try your suggestions tomorrow! As you see, yes, the needle valve ,that way i installed it is higher than the carb! |
RE: Problem problem problem
The needle valve location is not going to matter. All it is is a valve. The relation of the spray bar in the carb and the center-line of the tank is what is important. Almost every person here has suggested that you switch to a smaller prop, yet if haven't seen in any of your posts that you have. This may be the single most important thing and easiest to try, Have you done it yet?
You said the engine is used. It may just not have enough compression to create good enough fuel draw to pull the fuel straight up. Especially if you tank is not right behind the engine. Did you check to see if the clunk line has come undone inside the tank? Very common. |
RE: Problem problem problem
You may have a loop on the clunk line, inside the tank, and its against the front side.
Also, some time ago a friend of mine had the same problem on a engine that he bought used. The engine had a screw inside the muffler, after the baffle. When the engine pointed up, the screw jump to the exit hole and shut the engine off. |
RE: Problem problem problem
Check fuel line inside tank for cracks. Fuel line coud be cut inside the tank where it comes off the brass tube. Also clunk could be stuck forward in the tank resulting in a fuel draw loss when held verticle.
Grinder. |
RE: Problem problem problem
He says he has a good idle, so do not change the air bleed needle at all. The airbleed needle regulates the airflow though the small hole in the front of the carb. Sounds like it is right on.
Height of the needle valve is not a problem as long as the tank position is correct with the carb (and he says it is so). I am of the opinion the hugh prop is the problem, it lugs the engine down, keeps the RPM down (but helps the idle, right?). A 10 X 6 is plenty of prop for the engine, since it is not new, maybe a tiny bit to much, maybe a 10 X 5 or a 10 X 4 would be much better. And since it is a sleeve bearing engine, some Castor ought to be in the fuel. Good luck, Chip |
RE: Problem problem problem
RE: Problem problem problem - 10/31/2009 2:28 AM No New Messages still4given Click to learn more about the advantages of upgrading your membership here at RC Universe Posts: 828 Score: 100 Joined: 1/28/2006 Last Login: 10/31/2009 From: Victorville, CA, USA Status: offline The needle valve location is not going to matter. All it is is a valve. The relation of the spray bar in the carb and the center-line of the tank is what is important. Almost every person here has suggested that you switch to a smaller prop, yet if haven't seen in any of your posts that you have. This may be the single most important thing and easiest to try, Have you done it yet? You said the engine is used. It may just not have enough compression to create good enough fuel draw to pull the fuel straight up. Especially if you tank is not right behind the engine. Did you check to see if the clunk line has come undone inside the tank? Very common. _____________________________ Live simply. Love generously. Care deeply. Speak kindly. Leave the rest to God Hide Signatures (in reply to Kostas1) [View this members gallery] [Search users posts] [View My Models] Report | Rate post | Post #: 23 RE: Problem problem problem - 10/31/2009 5:12 AM No New Messages Vacaman Click to learn more about the advantages of upgrading your membership here at RC Universe Posts: 170 Score: 100 Joined: 1/10/2004 Last Login: 10/31/2009 From: Santiago, CHILE Status: offline You may have a loop on the clunk line, inside the tank, and its against the front side. Also, some time ago a friend of mine had the same problem on a engine that he bought used. The engine had a screw inside the muffler, after the baffle. When the engine pointed up, the screw jump to the exit hole and shut the engine off. Hide Signatures (in reply to still4given) [View this members gallery] [Search users posts] [View My Models] Report | Rate post | Post #: 24 RE: Problem problem problem - 10/31/2009 5:15 AM No New Messages grinder-RCU Click to learn more about the advantages of upgrading your membership here at RC Universe Posts: 711 Score: 100 Joined: 2/19/2003 Last Login: 10/31/2009 From: London, ON, CANADA Status: offline Check fuel line inside tank for cracks. Fuel line coud be cut inside the tank where it comes off the brass tube. Also clunk could be stuck forward in the tank resulting in a fuel draw loss when held verticle. Grinder. _____________________________ If your not flying, your not trying. Hide Signatures Guys, the pick up fuel line inside the fuel tank is too "stiff",strong ,i don't know how to express my self better, so as to make a loop. Also, the clunk, i checked double it's location inside the tank,i mean it's length, and it's not come in contact with the fuel tank vertical side. As for the compression. I think it's good. But even if it isn't how should i resolve this? I must go to my LHS and buy a 10x6 prop. Until then, i have thought that maybe a better glow plug will help. On the test run, i have used an OS A5, now i switched to a hotter A3. Will see. I was also advised, prior to take off the fuel tank and check it , to install temporarily on the side of the fuse a similar fuel tank and run the same test. If engine behaves the same, then the problem is in the fuel tank.;) |
RE: Problem problem problem
If you use a larger prop on an engine you should use a colder glow plug, a hotter plug may make it worse...though the A3 should be the right with the 10x6 prop.
|
RE: Problem problem problem
ORIGINAL: estradajae If you use a larger prop on an engine you should use a colder glow plug, a hotter plug may make it worse...though the A3 should be the right with the 10x6 prop. Hello all! Just came back from my LHS. I bought an APC 10x6 prop and a white plastic muffler to make my life easier....easier to start my engine using the starter. But it's raining too much outthere to risk it. So, probably tomorrow morning. I will let you all know... |
RE: Problem problem problem
Do you mean white plastic spinner?
Good luck! |
RE: Problem problem problem
1 Attachment(s)
Hi!
I have been using many OS LA .40 engines through the years and I can assure you that your problems is not related to the 11x6 prop. In fact the OS LA .40 have no difficulties swinging big props like a 11x6 and 12x4 if you fly at sea level . 10x6 is a prop size that is not that good for the engine, at least not in a high winged trainer like the Kyosho "Calmato" and planes like that with a span of 160cm. For smaller planes like a Q-500 racer weighting around 1700-1800g the 10x6 could be used though. Best 11x6 prop is the RAM , Graupner Cam-prop or the APC. A 10x4 or 10x5 is way to small for most airplanes where the OS LA .40 could be considered For best performance use an OS 8 or Enya 3 glowplug. Other good glow plugs are Nova-Rossi 4, 4A or Rossi 3 or 4. It is also vital that the tank is not too big. A 240cc tank (8oz) works good for a 6,5cc engine (.40).Best tank set-up is to use two clunks,one for pressure from the silencer and the other to the carb , this is called " and gives a more even fuel flow to the engine. Even better is to use a Tettra "Bubbleless" tank..but this isn't necessary for your engine. Remember to place the tank according to the "Tank rule"! Fuel! The OS LA series of engines run fairly good on 0% nitro, but they will run even better on 5%nitro. 10-15% nitro is just a waste of money on these engines as they throttle and run just as good on 5% nitro. 20% Castor oil, 5% nitro and 75% Metanol is a good blend. Placing the high speed needle 10cm from the carb is no problem. |
RE: Problem problem problem
ORIGINAL: estradajae Do you mean white plastic spinner? Good luck! Ups, yes...my bad...white plastic spinner :D Jaka, i don't get it...why use a small fuel tank rather than a 10oz,that i use? What's the deal? |
RE: Problem problem problem
Hi!
Problem with larger tanks is that the engine cannot cope with the changing pressure that occurs from full tank to nearly empty! Our engines go leaner as the tank empties. You probably know this already. This problem with the engine going leaner and leaner as the tank empties is worsened the larger the tank is. To remedy this lean out tendency it is vital not to use a too large tank and to use two clunks (Uni-flow system)in the tank for more even pressure distribution to the carb. But...a 300cc ( 10oz) will probably work okay too. But I would still recommend a 240cc (8oz) tank. On this tank you can fly for nearly 15minutes. |
RE: Problem problem problem
ORIGINAL: Kostas1 I used an APC 11x6 prop, 10% N Cool power fuel. Using all-synthetic 'Cruel Power' fuel, in a bronze-bushed ABN engine... It is just not like you! This engine should be run on fuel that has a lot of castor oil in it. Preferably even an all-castor lubricant package. Even though it is probably not the reason for your engine 'cutting out', I am surprised reading this from you! Check that the fuel-nozzle is situated about 0.5 mm shy of the center, of the carburettor's bore. It is adjustable in this engine and would have adverse effect if it is not. |
| All times are GMT -8. The time now is 08:47 PM. |
Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.