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Old 03-28-2010, 08:05 PM   #16
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Originally Posted by mudslinger View Post
http://www.rchobbies.org/cars_eng-tuning.htm

Scroll down to the lsn section.

You are wrong, if you have just come off of full throttle then the majority of the fuel is burned and after a few seconds the crankcase loads back up with fuel and brings the idle down. If your theory is true then why does a lean lsn cause a high idle, and why does your idle speed up when the fuel tank runs dry?
Yeah....what he said!!
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Old 03-31-2010, 05:58 PM   #17
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I'm new, but I've been playing with tune a lot and here's my personal experience with my particular motor (I'm sure different motors can react differently). When my LSN is way rich (3.75-4 turns out) my idle is solid, very stable, will idle the same exact low RPM all day and goes right to steady idle the second I come off of full throttle. When my LSN is leaner (2.5-2.25 turns out) my idle is slightly unstable, rises and falls when I come off of full throttle but will eventually fall and settle.
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Old 03-31-2010, 06:43 PM   #18
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How many motors have you tuned? Anybody can read but real world is different. Why does a lean lsn cause a high idle? Because your to lean. You either fatten it up or close your idle screw up some. When your wide open throttle your loading the case to maximum capacity of fuel. When you let of the throttle the case is still full. How do you stop this from happening to have a nice even idle. Simple you lean things out. Before you tell sombody there wrong tune some motors and get some real world experience.......
alot of people forget that a too rich hsn setting can still load the case. causing the engine to burn the residual fuel from the high end and having you compensate with the low end thus making it to lean.

set your idle gap and start at the top. once my motor is warm i can get a race tune in about a minute.
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Old 03-31-2010, 06:52 PM   #19
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I'm new, but I've been playing with tune a lot and here's my personal experience with my particular motor (I'm sure different motors can react differently). When my LSN is way rich (3.75-4 turns out) my idle is solid, very stable, will idle the same exact low RPM all day and goes right to steady idle the second I come off of full throttle. When my LSN is leaner (2.5-2.25 turns out) my idle is slightly unstable, rises and falls when I come off of full throttle but will eventually fall and settle.
turn you idle screw counter clockwise until it settles in. You could also be getting predetonation which is not good. You might think about switching to a colder plug or less % of nitro.

But i am 99% sure that your idle gap is too big or you need to richen you top about an hour. But this could also mean you need to richen your low end and lean your high end, but i don't know because i am not there. Best suggestion is to start at the top with you needles backed out, get your top end to where it is producing the best power (when the performance starts to diminish you have gone to far), richen it an hour and then start with the lsn.

Once you get it in the ballpark, a perfect tune could be one half of an hour (1/24th of a turn) away from perfect power.

also read your glo plugs
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Old 03-31-2010, 06:54 PM   #20
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arguing tuning on a forum? really? the guy needed some help and some of us tried to help him out. he's not happy with the engines punch, i think its the clutch or he's too lean on the bottom. the leaner on the bottom you are the lower the resting idle can be with the set screw, but the lsn has a bigger effect on engine temps than the hsn. thats why he is in the 260's (unless he's in a parking lot wide open as far as he can see over and over.)
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Old 04-03-2010, 01:02 AM   #21
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Originally Posted by j_blaze14 View Post
arguing tuning on a forum? really? the guy needed some help and some of us tried to help him out. he's not happy with the engines punch, i think its the clutch or he's too lean on the bottom. the leaner on the bottom you are the lower the resting idle can be with the set screw, but the lsn has a bigger effect on engine temps than the hsn. thats why he is in the 260's (unless he's in a parking lot wide open as far as he can see over and over.)
Yes I was very lean and had it all out of "wack" factory settings and shimming was actualy wrong corrected now. And yes also the clutches are very well worn soon as I can test the motor to see if its going in the right direction clutch shoes will be replaced also.
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