Oil Breather / Recirculation and Catch Cans

OK, finally got my catch cans and oil recirculation system done. I know this is mostly of interest to the supermoto guys, but with so many posts about the oil breather leaking oil, I thought maybe some others might be interested, too.

Here's a pic of all the parts ready to go. APA radiator catch can, Graves Motorsports carb catch can w/ bracket, and oil catch can, also by Graves. Custom aluminum bracket for the radiator and oil catch cans fabricated by me. I blasted then painted everything with a thermal dispersant paint - not that the stuff needs it, but once cured it's totally impervious to gas and solvents.


Oil catch can is made by Graves Motorsports and used on their supermoto bikes. I routed the oil breather from the valve cover to the tank, then the air breather line back to the airbox where it taps into a fitting on the WR airboot I installed. Bottom of catch can tube runs to a one way valve, then to a fitting I tapped into the inspection plug of the ignition cover. Basically all oil that is sprayed out of the valve cover gets recirculated back into the motor. Graves actually taps into the center cases for their return line, but I didn't want to split the cases to clean up the aluminum chips!



Carb catch can from Graves is pretty straight forward - just catches all the fuel overflow and holds it till you drain between rides.



Clean install. I should think about the Oil/Air seperator for myself. Good idea about putting the return in one of the inspection plugs.

thanks william!

Next time I have the ignition cover off, I'm gonna see if there's enough clearance inside to install a straight fitting right into the top surface of the cover - using the cap causes the fitting to be angled out slightly and a little more prone to catching on something. Straight into the top of the case will look a little better and be slightly more protected.

Might need a boss to be welded on the case cover to have enough 'meat' for a fitting. Not a big deal. Standard race car part for a Aeroquip type line.

I was thinkin the same thing - can't remember how thick the case is on top. I'll check it out next time the cover is off.

You did a great job. How about a pic of the whole bike.

Man that's a sweet install! I'm impressed on how you wedged all those parts into virtually no room? Gas tank must be stock? Can't see how anything could wrap around that catch tank and still fit. Good job!

Please show a pic of that entire bike.


so the oil catch can actually returns the oil that normal is lost via blow by back into the motor? so in "theory" your oil level shouldnt drop? also...who is the manufacturer of the radiator bottle?

that set up is sweet! and good job on the radiator & oil can mount.

Thanks, guys - here's how it's comin so far (pic from about 2 months ago)


Did have a gold rear sprocket and front disc, but the colors were kinda off, so I switched them to black. I have most of the wiring done now - only the "temporary" turns signals left to go. Also just changed the front caliper to a Brembo unit.

Rad bottle is from APA, and yes, the system should return all the oil to the motor that would normally be lost out the breather tube

Here's a quick pic I just took with the tank (stock) and shrouds in place


Holy sh!t!!! that bike is soooooo nice dude! killer job man. so I'm assuming by the turn signal comment you're trying to get it plated?

Yep - will be plated soon. headlight and tail/brake light are done. horn is a self contained battery powered unit. turn signals are LED units that will run off an 8 cell AA battery pack just till initial inspection is done, then off they come.

sweeeeeet dude...killer build up.

what did you use for a fitting in the airbox and oil fill cap for the oil/air seperator? and did you have enough breather hose after you cut it up, or did you have to get more?

also...is that a one-way valve in the oil fill cap line? the white piece?

the airboot and fitting are from the WR. on the inspection cap for the oil return, i just cut off the top of the stock cap and drilled/tapped for the fitting. in the future, I'll either drill and tap a nice aluminum cap, or tap into the ignition cover directly as mentioned previous. stock breather hose was plenty long enough - had some left over

yes, the white piece is a one way valve with a viton valve flap, so it should be impervious to the oil. Not real sure it would be a big deal without the valve (I don't think Graves runs one) but put one on anyway. I know the setup used by Mach 1 uses a valve:


The piece used on the mach 1 bikes is a bit more intricate than just a one way valve. Swatdoc, make sure you check the vent to see if it is blowing pressure out. I had one of APA's set-up's using the one way valve and it turned my engine into a vacuum cleaner (it was sucking air in rather than venting it out).

twin could you elaborate a little more?

Which vent are you wanting me to check? Just not sure since our terminology is slightly different.

Where was your bike sucking the air in from?

Simon from American Idol would even like that bike

Check the end of the hose on the upper right side of the catch tank with the monster energy sticker on it. I am trying to post a pic but it isn't working. If you still don't know which one i'm talking about let me know. I don't want anyone to have to go through what I did because of that hose sucking air (and debris) in to the engine.

on my setup, that hose goes to the airboot, and not the airbox, so if it did suck in some air, it would be filtered air.

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