[flybars]

Hello Tom. I too have the same problem with the crankcase breather hose spewing engine oil into the throttle body. My friends noticed that every time I got on it, it blew smoke out the back. I did a search on crank case breather hose and also noticed that my used xr440 has this same setup.
Replace crankcase hose with longer one and run it up and along upper frame to air filter box and zip tie it inside. Also put a Uni push-in breather filter (UP-123)(washable and oiless) on this end of hose. I plugged the front of throttle body with a vacuum cap. Now with the longer hose and running it up higher and further back, I'm hoping I can eliminate this problem. But if it still happens, I can clean the mess up easily by just opening the side panel. It looks to me that the design was to please the EPA? Now I won't be mixing my gas with oil.
When I went to clean the oil out of my throttle body, I had to dismantle most of subframe and tip it up and zip tie it to handle bars to be able to drain and spray clean with solvent. Must have been 5 different types of fasteners. There was about 1 1/2" of oil in there! I have a few more things to do before I can test my work, so I'll let U know after I ride. Bob