Bad LSN? Literally unscrews its self.

[mattyice]

Anyone ever have a LSN that backs out on its own. I'll have the truck running good then all of a sudden it will die, I look at the LSN and its unscrewed. Put it back to flush and truck runs for abit till it happens again. It's a older o.s. .18tm. Bad LSN? Can I replace the needle?

 

[tudordewolf]

Sounds like the o-ring on the LSN need to be replaced, part of their job is keeping the needle in position. You could probably use a set from a Traxxas carb rebuild kit.

 

[gandalfnz]

I had exactly the same on a friends nitro last night, HSN would turn all the way in just from engine vibration.
Replace the O ring.

 

[mattyice]

Sounds like the o-ring on the LSN need to be replaced, part of their job is keeping the needle in position. You could probably use a set from a Traxxas carb rebuild kit.

I ordered a new needle, so when ever that comes in I'll put it in and I'll let you know if it resolves the problem.

 

[Lukedavis]

I ordered a new needle, so when ever that comes in I'll put it in and I'll let you know if it resolves the problem.

As stated above its the O ring.

 

[mattyice]

I ordered a new needle, so when ever that comes in I'll put it in and I'll let you know if it resolves the problem.

Hey the needle is back ordered. I'd like to try and just put new O rings on it. Where can I get oh rings tiny enough

 

[500 Mike]

If you are in the USA I'd try A Main Hobbies.

 

[tudordewolf]

Hey the needle is back ordered. I'd like to try and just put new O rings on it. Where can I get oh rings tiny enough

The traxxas carb rebuild kit has a good number of the right size, and those brass cones are for easily applying them to the needles - you put the needle in the cone and roll the o-ring up over it from the narrow end.

 

[mattyice]

Are the type of oring flat on the sides? I look at the Traxxas rebuild kit but the orings look too large. Unless the sides are flat maybe?

 

[tudordewolf]

Are the type of oring flat on the sides? I look at the Traxxas rebuild kit but the orings look too large. Unless the sides are flat maybe?

They're round, but they're smaller than they look. The littler ones are 2mm in diameter and the "big" ones are 2.5mm

 

[mattyice]

They're round, but they're smaller than they look. The littler ones are 2mm in diameter and the "big" ones are 2.5mm

They are not wide enough and if I use two it's kinda janky. Needs to be 2.5×6mm I'm pretty sure. This is the needle.

 

[tudordewolf]

They are not wide enough and if I use two it's kinda janky. Needs to be 2.5×6mm I'm pretty sure. This is the needle.

View attachment 165848

Ah, bummer. Calipers might be worth using to get the exact measurements of the groove from.

This listing has 2.5mm OD x 1.5mm x 0.5mm thickness o rings and more, maybe one will match.

Or this one, 2.0 x 0.6 x 0.7mm