Runs Great, idles too high

[MaxxMasterS2]

my tmaxx starts and idles perfectly. I take it for a ride, and it idles way too high until I open the throttle 30-40% momentarily and ease offf, then it idles low, perfectly. It's cold here, like -9 C . is this an hsn or a lsn problem? I've tried both... i wondered why traxxas 2.5 was troublesome, I'm beginning to see. Someone tell me why after WOT it idles really high?


:shrug:

I said screw it and took it in the snow... huge snowbanks and jumps, camera next time. it was cold enough that the snow did not affect my parts.I had some serious drops, like 8 feet, onto the body. BUnch of thrashing and the only thing I lost was 1 pin to hold the body on. :hammer: it was sweet to bash my maxx. it needs chains for the snow. Big ones.

S2

 

[ZANDOR]

What are your temps?? IMO i whould turn your lsn in about a 1/16 of a turn

Edit) Its -9c check your temp first... get you maxx up to about 260 to 280f degrees.. you mite want to wrap your head with tinfoil to keep heat in..

 

[Tarant]

First off try the HSN at 4 full turns out and your LSN flush with the inner collar Your idle should be about 1-1.5 mm at the throut about the width of a credit card try that it is the factory setting & is a good place to start

 

[jon2]

Have you set your idle set screw? Have you retuned for your weather? What is the opening measurement in your carb venturi?

 

[Rolex]

It sounds like the barrel might be sticking. With the car off, hit the throttle as though you were running it, and see if it does the same thing. It it returns all the way in, every time you let go of the throttle, it's not sticking anywhere.
If it does it again, when the car is running, just leave it alone, and see if it will slow down to idle by itself in 20 seconds or so.
If it does, it's a sure sign of an air leak at the carb or the back plate.

 

[MaxxMasterS2]

I'm pretty new, I just broke in my engine, then leaned the hsn, then when I went to lean the lsn, is when the idle went up high. I tried lowering the idle speed needle, but it didin't seem to help.... if I go fast then let off the throttle, it revs high. if I give it just a bit then it idles fine. Help? I have no thermometer, and I 'm broke ass.

 

[Rolex]

There's a good possibility that your LSN is set too lean. When you lean the LSN, the idle will go up. Without a temp gauge, there's still a way to check if you're too lean. DO NOT try to reach normal operating temp by leaning it till it gets to 260 or better, because it's very cold out.
Start it, let it run for several minutes to get the temp up. Hit the throttle a few times just to blow the excess oil out, then when it's idling, pinch the fuel line close to the carb. It should speed up slightly, then shut off between 3-4 seconds. If it shuts off too soon, it's too lean and needs to be richened.
Adjust your LSN till it shuts off within that range, then adjust your idle if necessary.

 

[arawak420]

when i lean the hsn is it suppose to idle high? i leave the lsn flush

 

[.21Rc10GT]

well, it might affect the idle if you are turning the hsn, because that is the "main" fuel mixure setting. You may have to adjust your idle.

 

[MaxxMasterS2]

when i lean the hsn is it suppose to idle high? i leave the lsn flush

It definately idles lower after RICHENING the hsn. The problem seems to be fixed, I need to fine tune the idle maybe, but it idles pretty low, and doesn't take long to get there anymore. Thanks to all who helped me out, I'm big into bashing my T-Maxx now. I've got it out in the snow, gravel, pavement, grass, etc. It's done some flips, though not on purpose, and the body is starting to get damaged. I'm having a really good time with it now, and I'm even not that nervous to let friends drive it too.

 

[arawak420]

so i should leave the hsn at about 3-4 turns out, leave the trim at 0, and adjust idle speed with the idle screw? i have to get an idle screw it fell out.

 

[JESSE G]

so i should leave the hsn at about 3-4 turns out, leave the trim at 0, and adjust idle speed with the idle screw? i have to get an idle screw it fell out.

You might want to check out this thread I posted I got help from some very helpfull members. I set my hsn at 3 1/2 turns out on my .15 maxx seemed to work good to get it going then after I had set the lsn I went back and tweaked the hsn untill it ran smooth.


https://www.rcnitrotalk.com/forum/showthread.php?t=26397