Tinkman

Hi guys,
New to nitro. I started with electric and inherited a 62" Space Walker with an OS LA46 engine. I've been having idling problems and I don't know if it's my tuning, the glowplug selection or if the motor is just worn out. A good start would be to know what a healthy glow plug is supposed to look like.

Any help would be appreciated.

Thanks,
Joaquin

JohnBuckner

My Feedback: (1)

Welcome to RCU Joaquin. You need to describe exactly what the idling problems are. That is a better starting place. Also how many turns out for starting have you set the main needle and the next question are you aware of the mid range bleeder screw on the engine and how to set that? This screw is backwards of the main needle and the mid range is leaned by screwing it out not in.

John

JohnBuckner

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[..

scale only 4 me

My Feedback: (158)

Yes, the glow plug is the first thing to look at before you stat re-tuning
The filament should still look kinda shiny or at least normal metal looking,, if it's white and frosty or deformed looking it's gone cold and can go out on a rich idle setting even though it still lights.

If you are going to play with the needles, do start with a fresh plug, never tune to an old one no matter how good you still think it is.


good luck

Tinkman

Hi Guys, thanks for replying. The idling problem started happening last weekend. Before then, everything seemed good to go. Anyway, The engine would start right up and idle fine, then as I taxied out to the runway it would die just as I tried to start my roll out. Then is started dying during flight when I throttled back to idle.
I replaced the glow plug and retuned the air bleed and main needle bearing and it seems to be doing well on the bench, but I won't really know till tomorrow if it worked.
When I took the old glow plug out, it was black and shiny. To me that seems like it had been running too rich, but I don't really know since I have nothing to compare it to.

Thanks,
Joaquin

Tinkman

Sorry, "Main needle valve"

JohnBuckner

My Feedback: (1)

Joaquin its the main needle valve not the main needle bering you set. Its the needle you set either out the left side of the carburetor or on a remote just behind the engine depending on the age of your LA46. Replacing the glow plug is fine but you have already done that as you stated so the question now is from a fully closed (screwed in position) how many full turns out 360 degrees have you set the main needle valve for starting the engine? And also on previous running attempts have you ever leaned the main needle valve from that initial starting position (above).

Also you said you "retuned the airbleed", It would help if you would say how you "retuned" it

Your suspictions are correct and is likely rich possibly both the main needle as well as the airbleed that is why the questions

John

Tinkman

Hi John,
OK, so the first time I started the engine I set the main needle valve open two turns from fully seated. After I removed the glow starter and let it run at high idle for about 30 seconds or so, I ran it up to full throttle and started to slowly lean the mixture until the engine began to slow down. At that point I opened it back up two clicks. Now that I know where the optimum setting is at, I just open it half a turn when it's cold, run it up and do the leaning routine again.
To set the air bleed screw, I started with it half covering the air port. At idle, I picked up the plane and slowly raised the nose about 15 degrees or so. Initially, it started to die, so I turned the screw in half a turn and tried it again till it started to speed up. At that point I backed I off 1/4 turn.

drac1

My Feedback: (4)

Just curious. Why do you do this?

Tinkman

Because that's what it says to do in the OS manual for this engine. As I stated before, new to glows. If you guys have another method, I'm all ears.

scale only 4 me

My Feedback: (158)

Typically you shouldn't have to move more than a couple clicks either way from day to day,, sure if unsure it's best to start out on the rich side and tune by leaning the needle,, but a half a turn is way more than really needed.

you'll learn,, good luck

drac1

My Feedback: (4)

You shouldn't have to go through this procedure every day. I see a great deal of people who always fiddle with the needle, then wonder why they can't get their engines to run reliably.

Once set, don't touch it.

I never adjust the needle once set. If it starts to play up, then I know there is a problem somewhere.

scale only 4 me

My Feedback: (158)

Disagree strongly,,

Minor adjustments are always needed depending on differing atmospheric conditions

jeffEE

My Feedback: (5)

Your motor has a small hole in front of the carb. This is the easiest way to set the low needle on this type of carb. Open the low end needle a few turns, stick a T-pin in the hole and close the needle until it touches the T-pin. Pull the pin out and the low end is set. You should never have to adjust this needle setting more than a click or two. Sorry the picture is so small. but I think you can enlarge it.

drac1

My Feedback: (4)

Nope.

I fly all year 'round in temperatues ranging from - 3 degrees celsius to +38 and never adjust the mixture. A significant change in altitude is the only time I would expect to have to adjust the mixture.

Tinkman

Thank you all for your input. I had a chance to fly yesterday and the adjustments I made to the engine worked. No more stalls! Now I can fly without worrying about having to do a dead stick landing all the time and enjoy the flight!
Thanks again,
Joaquin

speedracerntrixie

My Feedback: (29)

Tinkman, glad you got it sorted out. A couple points in this thread I would like to clear up. First is that you really can't read a glow plug like a spark plug. Having a glow plug that has gone black at the bottom is a sign of being run lean. Most commercial fuel contain a small amount of castor oil. The black is castor that has burned onto the plug. Leaning until the engine sags and then opening up a couple clicks may still be on the lean side. Here in CA we don't get drastic weather changes so it is possible to set the needle valve and air bleed once and forget about it provided it is set correctly then as Drac states if it starts to act up you know something is amiss. If the engine ran well yesterday but has issues today you will not fix it by messing with the needles. Either something in the fuel system is blocked or perhaps a new plug is required. If you are running the correct settings ( a tad on the rich side ) your plugs should have just a slight transparent brown look at the bottom and last for months or longer. Having to replace your plug often is a sure sign of running lean. For that engine an OS # 8 plug is reccomended or any other long reach plug in the same heat range.

j.duncker

My Feedback: (2)

Not in my experience. Most of my engines would go a click or two richer in winter and lean out a couple of clicks in summer. Everything from a Cox TD 010 to a MDS 218. Of course if you change the fuel or plug you might need to retune. Otherwise I never altered the needle setting from week to week.

Any time I had to make a significant adjustment to an established engine/model set up that was a red flag that something was wrong with the plumbing.

scale only 4 me

My Feedback: (158)

How does what I posted,, "a click or two either way" or a "minor adjustment" = a "significant adjustment"? Words mean things, You guys just love to argue, even when a guy for the most part agrees with you,,

If you're telling me you can run a glow motor all year without ever touching the needles and get max performance with out ever being a little lean or a little rich,, then I call BS,, it has an adjustable needle for a reason.

good luck

speedracerntrixie

My Feedback: (29)

Scale, personally given your location I would have to agree with you however the OP is located in Central California ( not all that far from me ) and we dont have the same type of climate changes that you have in Ohio. Most Californians tend to puss out and not fly if its less then 60 degrees or hotter then 100.

scale only 4 me

My Feedback: (158)

I Lived in so cal for 43 years, flew at Sepulvida Basin near 25 years until 10 years ago when we moved back here, techniques are the same from my experience. You have high/low pressure and humidity changes in Cali just like anywhere else, it's not all about temps.

If your set and forget technique is working for you, great,, that's not what most guys that I know do.

good luck