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lsn setting

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Bkyd Basher

Bkyd Basher

RCTalk Addict
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Location
Stamford Ny
RC Driving Style
  1. Bashing
  2. Racing
Hey guys I'm having a hard time getting the lsn set correctly useing the pinch test. If I'm remembering correctly, if u pinch it and it runs longer than 3-4 seconds its to rich. I am at around 7-8 seconds and I've leaned out to half a turn. That seems way to lean to me. This is a brand new engine, all sealed and I'm on about 8 tanks now. Whats ur suggestions?
 
4 seconds is in the ballpark. 8 sec would be way too rich.
Be sure if doing the pinch test method that you are doing it immediately after a high speed run.
 
Thats what I'm saying at 8 secs, but I'm less than a turn out, almost a half. Shoudnt that be way to far in normally? What r u guys running approximatley? Even though i know all engines are different. And also it is about 90 degrees here, so maybe that would have a small affect on it also?
 
U want around 3 sec. U need to make sure the temps are dropping after 5sec after wot. Also that it takes off well and does t bog down. If its longer than 3 sec u prob won't be getting the best launches which takes the fun out of it
 
Forget the pinch test all together. Make sure your idle gap is set properly and richen the lsn. Run the engine up to temp and let it idle. Will it quit or load up after 15 seconds of idle? How about sluggish throttle response? Does it leave a spray of fuel on the ground when you accelerate after idling for 15 seconds? If so, that means it's too rich.

You should still have nice clean wheelie poppin' throttle response after about 5-10 seconds of idle, and it should not act like it's loaded up until about 15 or more seconds. Once you hit that ballpark area, you're within about an 1/8th turn of perfect.
 
Ok, Well i had it taking off real good. I would do a couple laps and come to a stop at the start finish line and simulate a start. It would take of real well and performs good. I was just worried about being to lean. It seemed to be kinda holding high idle for a sec or two when i came to a stop, so i kept backing down the idle little by little but didnt seem to do anything about the hanging idle. So i kinda figured i was a little to lean on the lsn. After about ten laps my temps were reading right around 245. I just get confused because it seems all the lsn and hsn and idle kind work hand in hand with one another. Just when i feel I'm getting the hang of it throws me a curve. I have the idle set to 1mm approx. Adjusted the hsn by performance, smoke trail, and temp to be safe. I will give it another run tomorrow. I'm probably pretty close. Thanks again guys. Dont mean to confuse ya, but hard to explain without actually bein here, but i appreciate your imput and help!!
 
is this a 3.3 engine? I've noticed that turning in the idle screw is the samw as leaning the LSN. Its another reason I dislike the 3.3. On a 3.3 the LSN only meters the idle and idle only. Any movement of the slide will pull the needle out of its seat.
 
Get it so it'll respond good and idle good. If the rpms still hang after a wot pass, try richening the HSN slightly til it goes away. You'll know if the lsn is too lean, most engines make a funny sound and begin to slowly overheat.

Remember to warm it up before you tune, a well tuned engine will seem rich until it warms up.
 
Thats kinda what i did, but as i backed off the lsn a little it seemed to load up and stall real fast after a pass. I got the rest of the week off so i will give it another go around. I'm gonna set the idle correctly and do some wot passes to get the high speed set where it works good with reasonable temps. What would u say is to high of a temp? 270 to hot? Then i will set the lsn to about 1 1/2 and lean in till it idles good for 10-15 seconds without a terrible sluggish take off. Like i said i had it running good and all but was just a heavy half turn out in the lsn. I always here to set it about flush and i was in past that but had the hanging idle so maybe i need to just richen it till the idle is normal and doesn't hang.
 
You need to richen the hsn if the idle hangs after a wot pass. Some of my engines act they have 2 different idle speeds, but I know they're just going into a 4 cycle idle from being rich.
 
Ok.might be close than. I did probably 12-15 wot passes and the temp reached 300. But the track i run at is pretty short and never run like that so i think it will never reach those temps on that track. Although the temps were up that high it never cut out or anything from being to lean. So i think once i get this lsn just right she will be right in the ball park. Like i said i really appreciate ur help. And really want to get a good handle on the tuning. I figure with a freshly broke in, sealed motor would b the time to really figure out what to do to make it run real good.Just nervous about goin overboard and harming the new mill.
 
extreme running will result in extreme temps. inaccurate way to base a temp reading.
 
Ya i just wanted to see how high it would get while running those wot passes. But like i said the track is quite short and i got up to like 265 max after a full tank nonstop run.
 
My buddy and i have switched a while back to S&W 20%. Only easy local option around other than traxxas brand,and the guy gives us a deal cause we buy 4 gallons at a time. Think it was 80 for 4. I actually got back out on the track yesterday and richened the lsn and 1/8 and it brought the idle down to reasonable and wasn't hangin anymore. So i think I'm pretty close, or close enough. Now that i have that close i should not really have to adjust that much anymore right? Just adjust the hsn for performance in the changeing weather conditions and temps ?
 

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