Building a snorkel.

[Fox17]

I want to build a snorkel for a 86 TRX250 and I have a few questions.

What size tubing would you use to not restrict air flow at all (if possible)?
What does "bringing all the lines up" mean? Like what all lines are we talking about?
And add any helpful info or if you know of a good tutorial a link would be nice too.

Thanks.

[backwoods boy]

carb overflow is 1 line mud will go up in it