[KD5ITM]

Who has installed a PCV valve on the crankcase where the crankcase breather hose goes into the air box? A long time ago somebody to talk about that on here but I can't find the post. What's the exact purpose of doing that? Is it just to keep oil fumes from getting into the air box causing a slight oily residue on the air filter?

[KD5ITM]

Pictures in the part number would be appreciated.

[Arizoni]

I think Ace did that to his with the idea that it would lower the pressure in the crankcase.

Lowering the pressure in the old Iron Barrels crankcase which housed just the crankshaft/flywheels, piston and connecting rod was/is important to improving performance and reducing the amount of oily mist that is blown out.
The stock Iron Barrels blow a LOT of oil out of the crankcase breather.

With the relatively huge volume of the UCE engines crankcase, IMO, it is no longer important.
The stock UCE engines blow little to no oil out of the crankcase when they are running.

[KD5ITM]

Well I just pulled out my K&N air filter and the rubber on the back of side opposite of the opening had a very thin film of oil on it. I wiped out the airbox and there was some oily residue in spots.

[hpwaco]

Amen to the iron barrels blowing out lots of oil!  My 02 es would regularly fill/overflow the "catch bottle".  Finally ran a hose back to the rear fender/license plate (like triumph did on my 500 scrambler) and put a duckbill on it.  Problem solved.  I periodically check my GTs airbox but its always clean/dry.

[KD5ITM]

Remove my air filter at the other day for the first time since installing it at around 6000 miles ago. Filter looks brand new. But there was a very thin film of oil on the back of the filter opposite the opening on the bottom side. And the airbox had a few spots with oil. Nothing one sheet of paper towel couldn't fix.

[Jellyroll]

I haven't seen that problem yet, but oil blows right past the nylon washer on the big bolt on the right side cover. I'm considering cork, treated paper, copper, or my own made from Permatex Ultra Black. Otherwise the engine looks like used flypaper. Or a 'proper British motorcycle'.

[KD5ITM]

There's a video on the Royal Enfield of Fort Worth Facebook page for November 22nd that shows a Continental GT with some racing stripes and modified exhaust. They eliminated the crankcase breather hose and installed a crankcase breather filter. Much like the crankcase breather filters that you see on valve covers that people put on their hot rods.

[KD5ITM]

Crankcase breather filter

[Richard230]

Crankcase breather filter

That modification is good for a $10,000 fine in California. 

[KD5ITM]

Just living in California is a good fine for something

[Guaire]

I put in the PCV valve with a hose that ends above the chain.

[hpwaco]

Is that a paper or gauze filter?  What happ ens if/when it gets wet?

[ace.cafe]

A "breather filter" also good for a loss of performance. Air is never supposed to be sucked in thru an engine breather. Only pushed out.

[Chuck D]

A "breather filter" also good for a loss of performance. Air is never supposed to be sucked in thru an engine breather. Only pushed out.

If you've only taught us one thing...