ATC200... what is this and how important is it?

[thatguy]

i have taken off fenders, air box, tank, and toolbox to clean the machine and tinker with it and found what looks like a breather tube or exhaust thing coming from the engine. its torn to hell and not really connected anywhere but appears it comes out of the engine to a t-fitting, one goes up and is open behind the seat and the other looks like it connected to the bottom of the airbox... but not sure due to heavy rawdawgin someone has done in the past!



http://i81.photobucket.com/albums/j2...1/P1400311.jpg

[HondaXRider]

Crankcase breather when I got my bayou 220 it blow the sight glass out while I was riding it (scared the crap out of my) because it was plugged. Probably need to replace to keep dirt and water out.

[emmie357]

Should have a hose out the bottom tube and down the back of the engine case so any oil blown out drips on the ground, rather then on the engine case.

[MattDragontamer]

Yea, it's the breather. Some models had the breather tied into the airbox drain tube. Not sure why... maybe the pressure and suction helps the airbox a little... or it's just a drain.
As stated, the more conventional method of setting up that tube is down the back of the engine to evacuate any oil spurts.

[emmie357]

Based on the pic it looks to have a T so it can go up to the airbox and down the back. One of my rides has that setup...
I know my YTM200's tie to the airbox, the wife's bayou220 has a T that goes down the back of the engine on one side and up to the handlebars on the other.

I always assumed that putting it to the airbox or up to the handlebars is to prevent water from getting sucked in, functions like a snorkel kit keeping the intake above water.

It looks to me like his yours has the T, but the bottom drain line is missing.
I would also check all the lines for clogging, they often get mud and oily crud stuck in them.

[tbren2]

not required in order to run, will run like crap though. Just a crankcase breather. I had one that was the same way and once i fixed it, it ran a whole lot better.

[thatguy]

so i read an article on a crankcase breather on wikipedia (...i know) and it looks like it acts as a PCV valve on a car. from what i could understand it will let oil or a small amount of gas out of the hole and the tee allows oil or solid debri to go down and out and the gasses to be cycled back into the airbox to re-use any potential unburned gas.. I hate that it attaches to the bottom of the airbox though, what if somehow water or dirt gets into the airbox? it goes down into engine thats where!

I do like the idea of recycling the released gasses so I need to find replacement tubing. Any ideas of tubing to use? maybe go to home depot and get plastic tubing?

thanks for everyones input on this!

EDIT: Sorry guys I looked at the shop manual and it shows where the breather tubes should go from the tee. The little hole at bottom of the airbox is not where it connects. The little nub thing attached to bottom of the airbox looked to me like it had been cut from the breather tube, but after closer inspection it is supposed to look like that. I guess the breather tube goes down to let oil drain and up to allow gasses to escape? Why not just have one down? I'm sure the small amount of oil could go down the same tube as the gas.. Oh well I plan to get some tubing and put it back the way honda wanted it 30 years ago!