Second fuel line going to muffler?

[bluebombersfan]

My FS 1/10 scale 2WD ATV has a second fuel line that appears to connect into the muffler. Just wondering if anybody knows what purpose that would serve.

 

[MotoGod]

It pressurizes the fuel tank to keep fuel flowing into the engine....since there is no fuel pump...and gravity would push the fuel the wrong way on most RC rigs.

 

[bluebombersfan]

makes sense but have another question

Is it normal for the muffler to spray out some nitro? I always get an oily mess spraying behind the thing. I just assumed it did that because there was a fuel line hooked up to it.

 

[neobart]

Perfectly normal, it's just oil. If it didn't, it would mean you are running to lean.

 

[MotoGod]

It really depends on how much Nitro is spewing out the pipe. If it's completely raw fuel...and a lot of it...you're probably running too rich. If it's some, but not a ton you're proabably OK, but I would search for the Nitro Tuning guide out here to help you out.

 

[robmob]

Read through these two informative threads.

They will be very helpful.

https://www.rcnitrotalk.com/forum/showthread.php?t=68224

https://www.rcnitrotalk.com/forum/showthread.php?t=60832