When adjusting a low-speed needle do you have to sometimes Rich high speed needle?

[newnitro2020]

Can somebody help me.
I need to know where you adjust a low-speed needle do you sometimes have to Rich the high speed some?

 

[newnitro2020]

dose anyone have a answer

 

[alfredwong2003]

The short answer is yes. For example, if your high speed needle was too lean to start with, some people will then make the LSN a bit rich to keep it going. So, it all depends on where you start from.

 

[newnitro2020]

The short answer is yes. For example, if your high speed needle was too lean to start with, some people will then make the LSN a bit rich to keep it going. So, it all depends on where you start from.

So from tuning it the high speed I mean first even if I did that.

There's a possibility by tuning a low-speed needle, it throws off the performance air fuel mixture ratio on the high end?

Reason why I'm asking this because I was outside yesterday and I noticed that the engine took a little bit to settle.
When I reach the high-speed needle while at the same time tuning the low-speed needle.


Everything seemed to went back to normal before I mess with the low speed needle.


So it sounds like to me that's a low-speed needle if you have your idle adjust it right which mine is perfect.

Sometimes you may have to redo a high-end just so you can make it rich to compensate the performance of the low end. One of the things I read in the nitro engine tuning vital is it says if you adjust the idle you might have to adjust the high-end.

But they was talkin about a idle screw.


I was thinking that if your idle screw is set perfectly where you don't have to touch it. And then you mess with the high speed needle for the whole time. That lets me know.

Please tell me if I'm right about this. Not just because of me but for someone else that wants to do searches on their own engines someday. Because if I'm right about what I'm thinking about then you sometimes have to double-check high speed needle after you mess with the low end.

 

[Rizzle67]

Usually when I hit this kind of tuning frustration I go back to original tune and work from there. When I say original tune I mean what the manual says for break in to fully tune.
As quick reference, most carbs are clockwise to lean and counter to rich. Both needles. As stated before starting from initial or static tune and fine tuning from there is easier than chasing what you have.

 

[johnnydmd]

The LSN is for starting/idle. Too lean, or too rich, it'll either not start at all, or it will idle very rough(too rich), or too high(too lean). If it's too far out either way, it can affect the HSN tune as well. Like others said, set it to the factory default, work from there. Usually the ideal setting is a little leaner than that. My experience is that you don't need to mess with it much after you get it at a good spot, and most performance tuning is through the HSN.

 

[alfredwong2003]

Everyday you go out, the previous day settings can be a slight difference. But once the engine is warm to normal working temperature, you should be close.

 

[Rizzle67]

@alfredwong2003 very true. Many people warned or complain about Nitro. I rarely have to tune my motors. Also small turns is all it takes. Once I have dialed in a good idle the rest falls into place nicely. With that said @newnitro2020 there is always hope. Patience and a good thermal gun to measure head temp and you will have a ripping motor in no time.

 

[newnitro2020]

@alfredwong2003 very true. Many people warned or complain about Nitro. I rarely have to tune my motors. Also small turns is all it takes. Once I have dialed in a good idle the rest falls into place nicely. With that said @newnitro2020 there is always hope. Patience and a good thermal gun to measure head temp and you will have a ripping motor in no time.

Can anybody tell me I'm correct on this? Remember I am tuning based on the perfect idle setting. And that is 0.5 millimeters





Okay well here's what I see when I mess with the low speed needle, the engine temperature will rise up even though you'll see smoke and you don't hear no hesitation.

That's when I take the high-speed and readjust it rich by an eighth of a turn.


Once I get it to where it gets to around under 275 then I'm good.


Then I continue to lean the low speed needle again until I reach that threshold.
I want two things I look for a reaching at threshold is does the idle ping or make a tin sound. Once I recognized one of those signs. Then I richan the low speed but at the same time I listen to see how the idle drop. If the idle drops where is low constant revs then it's pretty much set right.


But I think the most confusing of all is the conflict where the low in raises the temperature up thinking that you have reached the threshold. when really it's just taking some Supply away and causing the high needle to run lean. And the only way you'll know that you're reaching that threshold is by listening to the engine sound and how the smoke comes out.


the reason why I make this thread was because it was based on my experience.

 

[Rizzle67]

@newnitro2020 All I can say is from personal trials and errors. What are you trying to achieve? Race ready tune? Maybe try Utube vid on that specific motor. For myself I tune on cation. I am running richer to keep temps low. I do find sometime I am not burning fuel adequate so I then adjust. Still get 30 min run on a tank. My head clocks in at 210 on average 220 on hot days. For me I am a backyard/baseball field basher so near perfect tune isnt needed. Longevity and durability are my focus.
It is a bunch of tinkering. Once you do find your sweet spot you wont loose it. I hardly turn my screws to mess with it. My throttle is set to pull on Rx and push forward give me a choke effect. Once I have it running slight pull its out of choke not yet engaged. I will try to make a video.

 

[newnitro2020]

@newnitro2020 All I can say is from personal trials and errors. What are you trying to achieve? Race ready tune? Maybe try Utube vid on that specific motor. For myself I tune on cation. I am running richer to keep temps low. I do find sometime I am not burning fuel adequate so I then adjust. Still get 30 min run on a tank. My head clocks in at 210 on average 220 on hot days. For me I am a backyard/baseball field basher so near perfect tune isnt needed. Longevity and durability are my focus.
It is a bunch of tinkering. Once you do find your sweet spot you wont loose it. I hardly turn my screws to mess with it. My throttle is set to pull on Rx and push forward give me a choke effect. Once I have it running slight pull its out of choke not yet engaged. I will try to make a video.

What I'm trying to achieve is understanding the low speed needle.

And I mean in when you lean it out and affects the temperature where you might have to be a just the high speed.

Because by messing with the low in and affects the temperature. And then if you go at a high temperature like 275. And say that you haven't got to The Sweet Spot of the low in yet.
I just want to confirm that the same principle with temperature where you have the idle set right but you're messing with the low-end to tune it from factory setting.


And was wondering does it affects temperature where you have to retune the high-end to cool down engine? I'm trying to understand all this because I was outside on Tuesday doing this.

 

[alfredwong2003]

For myself, the LSN is used to make sure the engine does not get loaded when you go from idle to full throttle or stalled during idle.

 

[newnitro2020]

For myself, the LSN is used to make sure the engine does not get loaded when you go from idle to full throttle or stalled during idle.

Well I think I got the idea but I'm sort of skeptical and limbo on it.

Because there's so much confusion.

People who actually told me they've been in the stuff for more than 10 years or so say they still not sure.


But I truly believe if you lean out the low-speed needle I think the high speed reacts to the temps in a way that it refused to cool itself down.

Why some people may think it's a low-speed needle issue. It may not be it could be just that the temperature change within a high speed cuz of the low speed needle when you lean it you're letting less fuel going in.


And the job of the low speed needle is to cool down engine and if it rises up on idle.

Then you need to readjust the high speed.

That's the confusion and the conflict I'm facing here. The nitro engine tuning Bible says if you adjust the idle screw which is that Gap. You may have to adjust a high speed.

I'm thinking the same principle goes with the low speed needle. if you are only adjusted the low-speed needle and if your Gap is perfect on the idle.

 

[johnnydmd]

You may be overthinking a bit here.

Your idle game should almost always be 1mm, not sure where you saw .5, if it's not close to 1mm, you probably don't have the LSN right.

Essentially with the LSN, you want it in between the point where it's too lean to start, and where it's too rich and it loads up and won't idle. It's not a huge range in most engines. If your idle gap is 1mm, and it's revving to high, you're probably too lean, and right on the cusp of it being too lean to start up. If it's loading up and stalling when you take off, you're too rich.

What you should do is get the idle gap to 1mm, set both needles to factory settings. Start the engine, and work on the LSN to get the idle good (like I mentioned before, that's usually slightly leaner than the factory setting). Then start tuning the HSN for performance. Once you have that good, you can tweak the LSN a bit if your loading up and stalling, or idling too high.

 

[cbaker65]

You may be overthinking a bit here.

Your idle game should almost always be 1mm, not sure where you saw .5, if it's not close to 1mm, you probably don't have the LSN right.

Essentially with the LSN, you want it in between the point where it's too lean to start, and where it's too rich and it loads up and won't idle. It's not a huge range in most engines. If your idle gap is 1mm, and it's revving to high, you're probably too lean, and right on the cusp of it being too lean to start up. If it's loading up and stalling when you take off, you're too rich.

What you should do is get the idle gap to 1mm, set both needles to factory settings. Start the engine, and work on the LSN to get the idle good (like I mentioned before, that's usually slightly leaner than the factory setting). Then start tuning the HSN for performance. Once you have that good, you can tweak the LSN a bit if your loading up and stalling, or idling too high.

That is the way your suppose to do on a long LSN needle carb. ,because the LSN needle stays in the spray bar!..

 

[newnitro2020]

That is the way your suppose to do on a long LSN needle carb. ,because the LSN needle stays in the spray bar!..

You may be overthinking a bit here.

Your idle game should almost always be 1mm, not sure where you saw .5, if it's not close to 1mm, you probably don't have the LSN right.

Essentially with the LSN, you want it in between the point where it's too lean to start, and where it's too rich and it loads up and won't idle. It's not a huge range in most engines. If your idle gap is 1mm, and it's revving to high, you're probably too lean, and right on the cusp of it being too lean to start up. If it's loading up and stalling when you take off, you're too rich.

What you should do is get the idle gap to 1mm, set both needles to factory settings. Start the engine, and work on the LSN to get the idle good (like I mentioned before, that's usually slightly leaner than the factory setting). Then start tuning the HSN for performance. Once you have that good, you can tweak the LSN a bit if your loading up and stalling, or idling too high.

Yeah that's what I thought. There's no such thing as always having a 1 millimeter idle Gap.
You could make these smaller the smaller she can get a 0.5 millimeters. Anything smaller than that but just close the carburetor completely.



Originally I went by the manufacturer's recommendations but I also learn advanced stuff. If you find to the low in you got to have to break down the idle screw.


I'll try to get from everybody is there's only one video. That confirms this this guy at this Kyosho video said got to counteract the high speed with the low end after you set the low end.

 

[cbaker65]

I was talking to some of my nitro friends in private on Discord ,they say that they never tune a long needle
carb. by setting the idle gap first ,an said there was no point to do so because it will change anyway!
They attack the LSN first an set it as lean as they can get it with out issues ,then they do the Hsn. ,
then they go to the idle setting last ,because you end having to change the idle gap along each setting
of the others!..

 

[newnitro2020]

I was talking to some of my nitro friends in private on Discord ,they say that they never tune a long needle
carb. by setting the idle gap first ,an said there was no point to do so because it will change anyway!
They attack the LSN first an set it as lean as they can get it with out issues ,then they do the Hsn. ,
then they go to the idle setting last ,because you end having to change the idle gap along each setting
of the others!..

What you're saying sounds similar to what Jay QRC was doing and one of his videos from tuning from scratch.


When he did that he pretty much tune a combination of both needles kind of at once.

 

[nitrobrahhper]

Hey guys I’m new here after finally learning how to tune my short needle carb on my sh I ended up getting a new nova which has a long needle carb I seen someone tuning the long needle basically as you describe backwards of the short needle process
I have yet to touch my idle screw from factory on the long needle however I can say it’s about .5mm maybe even less “it’s a tiny tiny gap” for break in I just raised the throttle trim to keep it idling through the rich break in settings once I was able to hit the ground and start leaning out I had to start with the low speed as it was far to rich to move without a flame out I started getting that very responsive and able to idle without trim then I did a really slow semi long pull to see what the engine was doing through the lower curve I found nice crisp until about half way through it would gurgle very rich then clear out and scream like a bandit! Since this is my first 45000 rpm engine I got spooked and richened the hsn about an hour or two then begin leaning the mid needle and kept doing slow long pulls listening for a nice linear power curve so far I’ve found this much easier than the short needle carb how ever I will admit it comes down to idle gap if your idle gap is correct it makes tuning that much easier in any situation

 

[Greywolf74]

Hey guys I’m new here after finally learning how to tune my short needle carb on my sh I ended up getting a new nova which has a long needle carb I seen someone tuning the long needle basically as you describe backwards of the short needle process
I have yet to touch my idle screw from factory on the long needle however I can say it’s about .5mm maybe even less “it’s a tiny tiny gap” for break in I just raised the throttle trim to keep it idling through the rich break in settings once I was able to hit the ground and start leaning out I had to start with the low speed as it was far to rich to move without a flame out I started getting that very responsive and able to idle without trim then I did a really slow semi long pull to see what the engine was doing through the lower curve I found nice crisp until about half way through it would gurgle very rich then clear out and scream like a bandit! Since this is my first 45000 rpm engine I got spooked and richened the hsn about an hour or two then begin leaning the mid needle and kept doing slow long pulls listening for a nice linear power curve so far I’ve found this much easier than the short needle carb how ever I will admit it comes down to idle gap if your idle gap is correct it makes tuning that much easier in any situation

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