Engine Problem
 

First of all, Hello to everyone and thanks for having such an awesome site.

Ok, I picked up a trainer airplane at a local boot sale and brought it home. The plane came with a Tiger engine .40 installed and really the only things that were needed were electronics and fuel. I started the motor, tunned it on the ground (flat surface), and taxied it around. The engine has plenty of power, good acceleration. If you tilt the nose up around 15 degrees for a few seconds while the throttle is full open the motor almost cuts out. I am running 10% nitro and the glow plug is a brand new hot plug. I thought I had an air leak somewhere so I bought a new fuel tank, installed it and the same problem occurs.

Can anyone help? Any suggestions would be greatly appreciated. Thanks.

RE: Engine Problem
 

Well Gyro I had the same problem with my engine, I started a thread about it. I was advised many things, first thing, that when engine is running good on the ground without being nose up, you need to run it on rich, once engine starts running to max rpm, and it kinda coughs then turn needle valve back few clicks, and check transition 2 to 4 times then lift nose up. Infact what I was told that I was running engine lean, so I ran it on rich, though finally I found out the carb was the problem and taking air, still problem persists due to loose carb, Im gonna get another carb, my engine is HB 61 2C. I checked all the fuel lines, fuel line connected to the clunk, re-adjusted the position of fuel tank litter higher than carb nipple, now it atleast runs good but waiting for the carb. Check the carb, check the position of fuel tank, run it on rich, I hope it would work fine, im just very short experienced guy, Im sure a lot of well experienced guys would put in their advices to resolve your matter.

Good Luck

Mody

RE: Engine Problem
 

I'm a bit confused on the carb taking in air though. The propeller is just foward of the carb so all the wash air is being blown back, so regardless of what the orientation of the nose is the air is still flowing over it. I guess I didn't realize how much an affect a loose carb can have on the engine. Thanks for the help, I will try that tomorrow and see how it does.

RE: Engine Problem
 

Gyro,

I have also been advised about the pinch test for the engines. What size prop are u using for this engine. Is it Thunder Tiger Taiwan made engine or only Tiger? I know Irvine UK makes best engine, a friend of mine is using on his plane its 46 size engine, and that engine screams. Thunder tiger are good engines as well. Engine takes air from anywhere creates a problem which Im facing at the moment, sometimes I did experience some gunk or kinda pieces of dirt in the carb too, as our flying fields don't have grass, just soily land but hard surface. I wish your problem gets solved, and also wait for senior flyers advices, Im just a baby boy in front of them.

Good Luck

Mody

RE: Engine Problem
 

Well the engine is a Super Tigre engine from Italy, and the prop is a 10 x 6. Thanks again and let us know if your carb replacement solve your problem.

RE: Engine Problem
 

I will let you know, sure thing[8D]

Mody

RE: Engine Problem
 

Open the HS needle a couple of clicks rich, then run some fuel thru it. Might be a little gummed up.

RE: Engine Problem
 

The engine is too lean. First, check that there isn't gummed fuel/oil blocking the carb jets. Use the pinch test to determine the right mixture.

With the engine at full throttle and leaned out to "smooth running", briefly pinch the fuel supply line:
1. If the engine sags and dies immediately, it's to lean.
2. If the engine picks up speed adn runs a while, it's too rich.
3. If the engnie picks up speed, then starts to sag and die, it's about right. Open the HS needle about 2 clicks from that and it should run well in the air. It the engine sags and/or dies in loops, open the HS needle a little more. Some engines unload like crazy in the air and must be set rich on the ground.

There's only one proper way to set a ST low end needle:
1. Install a short piece of fuel tube on the carb inlet nipple.
2. With the throttle barrel at idle position (engine NOT running), hold the carb throat to your ear and blow into the fuel tube.
3. Gradually open the idle needle until you can JUST hear air blowing through the carb. It'll be within 1/8 turn either way of being right.

Dr.1

RE: Engine Problem
 

For what it's worth: With the engine properly tuned and running perfectly on flat ground....... if you tilt the nose up the mixture leans out a bit, I suppose because the fuel has to flow up to the carb instead of straight/level to it. Err to the rich side, open your high speed needle a couple clicks and try it again. An over-rich mixture isn't near as dangerous as an overly lean mixture. You engine will run slightly rich in level flight and with the nose up will run just as it's supposed to. A lean mixture has always stalled my engine, a rich mixture will just leave a smoke trail for the most part.

My experience so far......

RE: Engine Problem
 

Even though you replaced the tank, are you certain the clunk is free in the tank?

RE: Engine Problem
 

Be sure the klunk is about 3/8" away from the rear wall of the tank, too.

Dr.1

RE: Engine Problem
 

I always had a hard time following the "2-3 clicks rule" "once it's running nice and fast (lean), richen it up 2-3 clicks."

I agree w/ the statement, but I have found that if you have it running at full throttle lean, there will be very little smoke coming out of the muffler. At full throttle, richen it up until you hear a slight drop in rpm and you will start to get some smoke out of the muffler.

Also, the fuel line pinch test is a good verification that you've got the right setting. Your fuel air mixture may need to be adjusted too, though. This can be tricky if you don't know what you're doing. I'm not too familiar w/ that engine, so I don't even know if it has the 2nd needle. If it does. screw it all the way in and back it out 2-3 full turns. Start there and get it adjusted so that there is plenty of throttle response from idle to half throttle and also plenty from half to full throttle. You should be able to go from idle to full throttle and back down w/ no "delay" in rpm, and no engine dying at the end.

Good luck!
-Erik

P.S. Maybe the guys at your local flying field can help you tune your engine!

RE: Engine Problem
 

Note that the amount of smoke the engine produces is highly dependant on factors besides how rich the engine is. Things like the brand of fuel (or, more to the point, the brand and types of oil in the fuel) can affect how much smoke is produced, and other factors such as lighting, wind, and the prop used can affect how visible the smoke is on the ground.

I use the pinch test, and find it works very well. When I can't pinch the fuel line, such as on a cowled engine, I peak up the engine, then open the needle a little at a time until I hear the RPM change. On many engines, 2-3 clicks isn't enough, you want to hear the RPM come down off peak.

RE: Engine Problem
 

Thanks to everyone for the help. I successfully tuned the engine. I had to richen the mixture a lot. Now it works without a problem and I have full power upon demand. Hopefully tomorrow I can fly the plane for the first time. Wish me luck. By the way England is a terrible place for flying. i.e. Cold and Foggy/cloudy all day long.

Gyro

RE: Engine Problem
 

The first response to the "engine dies when nose up" problem should really be "try to richen it up" first.

I've seen several threads where people immediately suggested an air leak.

In the beginners area, what would be the most likely scenario is an untuned and new engine that really hasn't been broken in yet.

RE: Engine Problem
 

is it possible to restart an engine in mid flight if it dies? I am afraid that I might lose the engine while flying and I will have to do a forced landing.

RE: Engine Problem
 

only if it's an electric engine. otherwise can ya say DEADSTICK! and that can get pretty interesting in a hurry. not too bad if you have enough altitude and are close enough to your landing, but it can be ugly otherwise.

RE: Engine Problem
 

I will have to do a forced landing.

Sooner or later, you WILL have to make a forced landing. Sooner or later you WILL crash. Those are two Laws of R/C. However, you should make sure your engine is as reliable as it can be. Get it properly broken in and tuned on the ground, then let an experienced pilot fly it a couple of times, just in case it DOES die.

Dr.1

RE: Engine Problem
 

I don't want to open a can of worms here, but search on this site for glow plug options. You might want to try a couple different ones just for kicks. I bought an old plane that come with an "idle bar" plug. A switch to an OS#8 (as recommended by others on here) improved how my engine runs completely....

Just a thought.

RE: Engine Problem
 

I've seen several threads where people immediately suggested an air leak.
Yup. Look for the simple fixes first.

I don't want to open a can of worms here, but search on this site for glow plug options.
No can of worms here. Glow plugs are different as night and day. What a pilot usually ends up doing is picking one plug he likes and sticking with it on all his similar-type engines.

Now, HERE'S a can of worms - I'll recommend a plug! Personally, I like the McCoy 9 or 59 plugs. They're reliable and tough. The 59 is a hot plug, good for low nitro, low compression, rich idle, and cold weather conditions. The 9 is colder, and works well with 25% nitro and high compression engines, like the Webras.

Dr.1

RE: Engine Problem
 

Thanks for the input... I would first like to say that I flew my plane for the first time today. I must admit, my takeoff was awful but the landing was beautiful. I was also brave enough (or dumb enought) (or maybe both) to do a set of barrel rolls. It was great.... Oh, and the winds were 12 knots. Not bad for the first nitro flight huh?

As for the plugs, I use 10% nitro and a OS #8. I do have a bit of lag when I throttle up??? Maybe I'm running the engine too rich?

I'm just curious, but what is an Idle bar plug? I'm sorry for all of the questions. I have been in the nitro scene for a while but I must admit , I started with r/c trucks and it is definitly not as complicated as with aircraft.

RE: Engine Problem
 

sounds like a usual first flight...(although some bounce on landing, quite hard in fact). Congrats! It maybe slightly too rich, but it helps to pull the engine off, open it up,(change the plug while you are at it), clean the with rubbing alcohol, and replace the fuel lines(keep the old ones just in case). Swish around some alcohol in the fuel tank and dump it out, letting it fully dry then reassemble and go for an engine test..if this doesn't solve it..let us know..

RE: Engine Problem
 

Congrats Gyro:D upon your flying, people normally take off good, but landings are bad, but your take off was bad and landing was good, great !!! Keep it up. Well, This sunday Im going to flying field in the evening, and it would be afternoon there in UK.I'm gonna let you know how did it go with my plane with HB engine. Idle bar plug I saw for the first time in my HB engine, that plug as a little bar across on the top of the plug right above of glow filament. I started a thread about the sizes of plugs but some how, I forgot lol :) the purpose of idle bar. Im sure someone is gonna tell it here.

Good Luck gyro again

Mody

RE: Engine Problem
 

I am hooked on flying!!! Yesterday I flew 3 tanks. The engine is still acting up. I pulled the carb, cleaned it, and changed the fuel lines. It still is running a bit rich, i'm sure. My high speed needle is different from what you all described. It is rod shaped will a bend at one end, kind of like an "L" shape. the hole in which it goes into is elongated making the needle very loose. On run up the needles "L" shape weather vanes with the thrust of the prop, and it richens the mixture or leans it out. I tried using rtv to make the needle a bit more stable but it didn't work. I rigged a rubber band from the needle to the cooling head to put some tension on the needle and that works for now. Since replacing the carb is not an option at this point (hobby stores closed Sundays and Mondays) What should I do?
My fears of forced landings have been overcome. I had to do 4 landings yesterday when the engine quit in mid flight, luckily I had plenty of altitude to execute some safe landings. Well friends, I'm going to take her up again (day 3), I'll talk to you guys later.
Mody
Let us know how you did. Whish you luck!!

For all of those guys who have posted on this thread, I thank you again for all of your suggestions/ solutions and support to my engine problems. Lets keep those wings up in the air where they belong!!!

RE: Engine Problem
 

Sounds like your little spring clip that holds the needle from rotating broke off - you will get that at the hobby shop. A temporary fix is to put a piece of fuel tubing over the needle and the housing to hold it from rotating.