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Old 12-24-2012 | 04:26 PM
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Default Engine idle problems 2

So I don't know whether my old thread got deleted or glitched or what. If it's there and I just can't see it, go ahead and delete this.

I'm having problems adjusting my LSN and idle screw. I've gone through the tuning bible and can't figure it out.

Basically, either the engine idles too high the whole time, then stalls, or it idles too high, then when I turn the idle screw down, it stalls, or when I lean the LSN slightly, and hit the gas, the engine immediately dies.

What do I do?
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Old 12-24-2012 | 04:37 PM
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Originally Posted by zeBugMan
So I don't know whether my old thread got deleted or glitched or what. If it's there and I just can't see it, go ahead and delete this.

I'm having problems adjusting my LSN and idle screw. I've gone through the tuning bible and can't figure it out.

Basically, either the engine idles too high the whole time, then stalls, or it idles too high, then when I turn the idle screw down, it stalls, or when I lean the LSN slightly, and hit the gas, the engine immediately dies.

What do I do?
Sounds like the LSN is to rich. Take the air filter off and set the idle gap to 2mm (about the width of a Xacto blade). Then start the motor and warm it up. Give it a couple of full throttle blips, listen to see how long it takes to idle down. Start leaning out the LSN until it does not idle down, then set the idle screw to the correct idle. At this point the HSN will probably be to lean, richen the top end until you see constant smoke while accelerating. Temp the motor after a couple of min of driving. It should be around 230. Only make small changes, in one hour increments, at a time.

It always helps if you are at the track and get someone to help that knows what is going on as you drive it.

Good luck and Happy Holidays.
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Old 12-24-2012 | 04:47 PM
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I did set the idle gap to 1-2mm, and the car does idle, and when I gas it it does go. However, when I lean the LSN about a quarter turn, THEN it dies when I hit the gas.

The other issue is that it does not idle down at all. When I have it so that it does idle, it idles incredibly high, nearly half throttle. Even when the buggy is on the ground and the wheels aren't spinning, the engine revs are still super high.

Does that mean that it's still too rich?
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Old 12-24-2012 | 05:00 PM
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Originally Posted by zeBugMan
So I don't know whether my old thread got deleted or glitched or what. If it's there and I just can't see it, go ahead and delete this.

I'm having problems adjusting my LSN and idle screw. I've gone through the tuning bible and can't figure it out.

Basically, either the engine idles too high the whole time, then stalls, or it idles too high, then when I turn the idle screw down, it stalls, or when I lean the LSN slightly, and hit the gas, the engine immediately dies.

What do I do?
What brand of engine are we talking about? Is it broken in or new?

If the engine is broken in, don't set the idle gap larger than .7mm
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Old 12-24-2012 | 05:01 PM
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check the throttle trim, normally a small move of the servo is needed before the carburater will be moved. If there is no small moment between them the that is the cause.

Keep the ignitor on, if that does solve the stall then you will notice if the engine is to rich or to lean.

And another cause is the glowplug, a to cold or an old plug can give such problems.
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Old 12-24-2012 | 05:24 PM
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Originally Posted by nitroexpress
What brand of engine are we talking about? Is it broken in or new?

If the engine is broken in, don't set the idle gap larger than .7mm
It's an SH .28 engine in a new Hurricane XTR. I broke in the engine, and I don't have any starting point as for ballpark tuning settings.
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Old 12-24-2012 | 05:41 PM
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This may or may not help.

http://www.rctech.net/forum/offroad-...run-right.html

http://home.comcast.net/~98gmarquee/...cDocs/SH28.pdf
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Old 12-24-2012 | 06:31 PM
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Says the LSN is preset. However, when I set the needle back to factory, raw fuel spits out the exhaust. I take it that's normal then?
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Old 12-24-2012 | 06:34 PM
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delete me mods
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Old 12-24-2012 | 06:38 PM
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Originally Posted by zeBugMan
I did set the idle gap to 1-2mm, and the car does idle, and when I gas it it does go. However, when I lean the LSN about a quarter turn, THEN it dies when I hit the gas.

The other issue is that it does not idle down at all. When I have it so that it does idle, it idles incredibly high, nearly half throttle. Even when the buggy is on the ground and the wheels aren't spinning, the engine revs are still super high.

Does that mean that it's still too rich?
I think you have a few things going on.

1. the clutch isn't engaging if the engine is reving and it's not going. this is also the reason for the stalls more than likely. if it has the standard kind of clutch the spring is probably broken. then the shoes get jammed in the housing causing it to stall out sometimes.

2. since it's reving that high on it's own, you have an air leak in the carb. check the base oring and make sure the carb is down all the way and the retainer nut is nice and tight.

any time a nitro engine starts stalling for no reason the first thing you should suspect is the clutch. I've even had a pin in the flywheel back out and touch the bell causing stalls.

Last edited by mtpocketsracing; 12-24-2012 at 06:48 PM.
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Old 12-24-2012 | 07:03 PM
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Originally Posted by mtpocketsracing
I think you have a few things going on.

1. the clutch isn't engaging if the engine is reving and it's not going. this is also the reason for the stalls more than likely. if it has the standard kind of clutch the spring is probably broken. then the shoes get jammed in the housing causing it to stall out sometimes.

2. since it's reving that high on it's own, you have an air leak in the carb. check the base oring and make sure the carb is down all the way and the retainer nut is nice and tight.

any time a nitro engine starts stalling for no reason the first thing you should suspect is the clutch. I've even had a pin in the flywheel back out and touch the bell causing stalls.
But it's a brand new engine D: I haven't even hardly gotten started tuning yet!
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Old 12-24-2012 | 07:26 PM
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Originally Posted by zeBugMan
Says the LSN is preset. However, when I set the needle back to factory, raw fuel spits out the exhaust. I take it that's normal then?
Factory settings are generally for break in and very rich. Don't be afraid to lean it out.
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Old 12-25-2012 | 07:14 AM
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If its brand new, you broke it in right?
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Old 12-25-2012 | 09:51 AM
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Originally Posted by zeBugMan
But it's a brand new engine D: I haven't even hardly gotten started tuning yet!
that $10 a day china worker was probably having an off day

no but seriously, as much as we all would like things to just work out of the box most of the time they don't or require some proper setup and tuning.
there is even a sealant for carbs for just this very reason.
http://www.amainhobbies.com/product_...uretor-Sealant

btw, don't listen to the one review of it that says it's the same as the autoparts store sealants.
not all sealants are the same. most of them you cannot use in contact with fuels.
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Old 12-25-2012 | 06:32 PM
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Have you tried tuning with the main (high speed) needle?? If your idle is fine, then once you hit the throttle, there's too much of a variance of air/fuel causing it to die....its really hard to tune a motor via forum, but I would try leaning the high speed needle 1-2 hours, and richening the low speed 2-3 hours...all this is with your idle gap @ 1mm...other than that, set everything back to factory settings and start over
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