Carb vent hose catch can???

Was looking through a magazine and they are selling a catch can set up for the carb vent hose. Like the issue with the motor breather hose they are stating that dirt can be pulled through the carb vent hose and then obviously into the motor. Is this fact or just another scare you into buying it gaget?

i haven't heard of dirt being sucked up those hoses but i have seen one-way filters that go on the end of the hoses, maybe theres some plausibility to it.

Because of the design of the FCR, the fresh air feed to the starter circuit comes directly from the float bowl, rather than from the mouth of the carb, where it would get filtered intake air. If you draw air from the float bowl, it has to come from somewhere, and the only source is the vent tubes.

So, be careful of where the tubes are when cold starting. Otherwise, during normal operation, there is very little volume of air moving either way through the tubes. Just enough to keep the atmospheric pressure balanced between the outside air and the float bowl. The real reason for catch cans is to keep gas off of paved race tracks for road racing and Super Moto.

The info was coming from Dirt Bike magazine where a company by the name of F2 Racing was doing some tinkering with the carb on a KLX 450 to open it up a little. The catch can was one of the add-ons among others they did and their reasoning was this

The biggest thing that trashes valves is dirt getting in the engine.There is a filter on everything, the air filter, the oil filter, etc. Except for one place...the carb vent lines. The first place the dirt goes is right into the carb and straight into the intake. Fortunately, the F2 trash can was developed to catch the junk before it makes it to the carb.

Either way, I don't think I'm too worried about it, just figured I'd post it and see what everybody thought.

another thing the catch cans are good for is keeping the fuel from your ground water. we are mandated by the supermoto sanctioning bodies and tracks to have catch cans on the oil (crankcase vent), radiator, and carb so no liquids can be spilled on the track. mostly they are concerned about liquids on the asphalt. not the dirt but, doing this could help keep the "greenies" off our backs about one other thing.

i run an advanced performance accessories coolant over flow tank, that actually re-feeds the system in a case of over heat, just like a closed system on an automobile. i run a graves motorsports crankcase vent can, and graves carb can. no dangling hoses, no leaking liquids. the graves oil can can be fitted to return the oil to the motor so it is a total no oil loss system, same as the apa coolant resi. ski

their reasoning was this

The biggest thing that trashes valves is dirt getting in the engine.There is a filter on everything, the air filter, the oil filter, etc. Except for one place...the carb vent lines. The first place the dirt goes is right into the carb and straight into the intake. Fortunately, the F2 trash can was developed to catch the junk before it makes it to the carb.

Here's what you do: drain the carb using the little Allen screw on the bottom of the bowl, then pull the main jet access plug and have a look. How much dirt do you see?

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