NOOB tuning issues

[greenwing7]

I was wondering if some of you more experienced nitro folks could explain to al lthe new people in nitro what effects each needle (HSN, LSN, and idle needle) have on the performance and how to adjust them accordingly
like if you are running too hot, idling too fast, or not Idling at all or if this is too broad
thanks

 

[Tarant]

Ok the HSN will change the temp. if u turn it counterclockwise u will richen the engine and bring the temp down and if u turn it clockwise u will lean the fuel and it will rasie the temp and this is always the first needle u adjust.then the LSN this is for that punch off the line and it works the same as the HSN but it will adjust how much fuel enters the engine and this should be adjusted only after u have the HSN in the correct postion so it is secound and last the idle and this should be set so u have a 1 to 1.5 mm gap (about the thickness of a credit card) in the carb throat when u have the brakes aplyed
I am sure this is how it works but if I am wrong someone will correct me

 

[greenwing7]

so the Idle screw sets the amount of opening/gap there is when the carb is "closed"

 

[Tarant]

correct. when the carb is "closed" or in idle, if the gap were to close all the way it would kill the engine

 

[jon2]

Ok the HSN will change the temp. if u turn it counterclockwise u will richen the engine and bring the temp down and if u turn it clockwise u will lean the fuel and it will rasie the temp and this is always the first needle u adjust.then the LSN this is for that punch off the line and it works the same as the HSN but it will adjust how much fuel enters the engine and this should be adjusted only after u have the HSN in the correct postion so it is secound and last the idle and this should be set so u have a 1 to 1.5 mm gap (about the thickness of a credit card) in the carb throat when u have the brakes aplyed
I am sure this is how it works but if I am wrong someone will correct me

Almost got it. The HSN is the needle that controls the major flow of the fuel coming in and the LSN controls the fine tuning or the fine stream of the fuel coming in. HSN will determine the top speed of your ride whereas the LSN contorls the accelaration or "punch" off the line. The idle set screw controls the idle speed of the engine by opening the carb gap when at idle. Normally at idle you want the idle set screw to be around 1mm.

The correction I wanted to say is BOTH NEEDLES can cause your engine to either heat up or stay relatively close to 200 and 250. Its a wide range due to some people tune their engines to run at 220 most of the time or even240-250. Now I know that some engines like to run better when they are closer to 260-275...The 2.5 Maxx engine is like this IMO.

 

[greenwing7]

are all (or at least tht majority) of engines counter clockwise to lean and clockwise to ritchen the needles?

 

[CorradoPsi]

all engines are clockwise to lean, counterclockwise to richen.

 

[Plaidfish]

as far as I know they all are.....

 

[greenwing7]

all engines are clockwise to lean, counterclockwise to richen.

thats what i meant LOL
since they are right handed threads, you are essentially screwing in the needle, thus cutting off the flow of fuel a little bit every time you turn the needle

 

[Mugen MTX-2]

I got a hopefully simple question also, how do you know if you idle mixture adjustment is correct? (I'm my case a Nova Top TSR12S3)

 

[Pinblaster]

I got a hopefully simple question also, how do you know if you idle mixture adjustment is correct? (I'm my case a Nova Top TSR12S3)

When you have the Idle mixture close, you should be able to pinch the fuel line closed and the engine should run between 3-5 seconds before it dies. Also you will have good punch off the line when the engine sits at idle for a few second.