I'm not sure if this is applicable, but my xrl650 originally had a charcoal canister with all the hoses routing crankcase fumes back into the airbox. A short experiment with synthetic oil in a tired big bore resulted in some severe oil consumption and a saturated K&N.
After re-sleeving and boring back out the the max of 102.4mm for 675cc's, having the valves done, a mild cam, and going back to castrol 20w50 i didn't want to leave the crankcase vent running into the airbox. I bought a K&N crankcase breather, but couldn't really find anyplace suitable to mount it.
What I ended using was a small sintered bronze muffler (3/8" NPT) used in
pneumatics ziptied to the inside of the frame tube. It seems to work just fine tucked in out of the way and up high enough to not see any water in stream crossings. McMaster-Carr p/n 4450K3 $2.28 ea. Hope this helps