Hi everyone. New to the forum and recently picked up my first bike. An 06 KLX 250. Bike runs great no issues, however previous owner stated he deleted the PCV system and that's why there's no filter over the crank case breather hose and just a dead end cap/cover looking thing. I'm sure this has been answered before but can anyone explain to me more about a PCV system delete and what other things I should look for or be checking out. Thanks in advance for your help/advice.

Cheers.

 

Are we talking about the crankcase vent tube that goes into the airbox or are we talking about the fresh air feed that goes into the reed valve setup of the exhaust system for a secondary burn? I'm guessing the fresh air exhaust system because you can't/shouldn't block off the crankcase vent. You can reroute the crankcase vent hose and leave it open to the atmosphere, but that's not a good idea. Some use a small K&N style filter on this crankcase vent hose to keep dirt out and some have actually used an automotive style PCV valve with the end open to the atmosphere. On the fresh air exhaust system, some have just blocked off the hose and the reed valve in the head to disable the fresh air system. I'm thinking this may be what you're describing.

 

Hi. I asked the previous owner if I needed to put a filter on the crankcase vent tube as it is currently open to air and that's when he responded with no need to worry because he did a PCV delete. I was concerned as there was some debris that I was able to clear out of the crankcase vent tube and wanted to put a filter on it so it didn't keep getting clogged. And he made it seem like it wasn't an issue anymore 🤷‍♂️. Thanks. And yes, it's the tube the runs off the air filter down the the right rear side of the swing arm/rear wheel.