CRF Breather Tube from Valve Cover?

[Lasher]

What are you supposed to do with the breather tube that comes off the vavle cover?

On the CRF bike, a tube split into two directions. One was down the back of the motor (probably to catch splashed oil) and the other was routed to the airbox, inside the filter.

On my son's Walsh Hybrid, using the 250R air box with Walsh adapter I do not see anything for this tube to connect.

I was thinking of running the tubing to the air box, but it would not be inside the air filter. Should I attach a small pod type filter on the end?

Basically...what do I do with this tubing?

[JAG Motosports]

just run my sons straight down below the frame.. they do sell a conversion kit for the dirt bikes that run it straight down with a filter on the end but most on thumpertalk dont use the filter. I felt like i would suck dirt in the head but in a year I have never found any signs. I know some trx 450 guys also take theres out of the box and straight down.

[Lasher]

Right now I just put a couple outerwears over the connector on the valve cover to keep dirt out but oil gets splashed out with that all over the back of the motor.

I cannot imagine there would be suction through the tube so maybe an open tube would the ticket, pointing down.

I will go search thumpertalk, I figured the dirt bikes just left it stock running in to the air filter.

[Groves187]

I just bought some .500" clear tube from Low's and ran mine between the swinger and motor. No filter.

[Lasher]

I have the complete tubing from the CRF dirt bike. But you guys are making it sound like running tubing straight down is the ticket.

[JAG Motosports]

one reason to get it out of the air box is if he is racing and for any reason the case pressurizes and blows oil out, the air filter gets covered causing running isses

[Lasher]

Just spent the last hour here at work reading 9 pages of threads on Thumpertalk about this tube.

Appears it is routed to the airbox for EPA emissions stuff. Recycle back into the motor. The downward facing tube with the cap is for water and oil to flow.

While one person talked about modifying the set up so the exhaust acts like a pump to pull the valve cover gases (blowby) out of the motor, most mention just running a straight tube.

There was some that talked about dirt/dust making its way back up the tube, especially when starting in deep water. But it did not seem like a big deal.

Other put filters on the end of the tube but then talked about what happens when the filter is clogged during a race. More problems.

One thing I did like to hear was an open tube pointing down will help with jetting issue on the carb bikes.

Thanks guys. I am going to run a straight tube down without a plug or filter. I will check to see if there is any suction when starting or running.

[atvmxer79]

I use the dirt bike tubes off the valve cover. Where it splits and goes down by the sprocket is stock. I remove the tube that on the dirt bike goes to the intake boot. I then run a tube from the split into the front of the airbox and out the back of it. The tube actually hangs over the sprocket and lubes the chain with the oil that blows out. I have used the setup for 3 years and others I know have used it longer than that without issue.