Hey flyguybill, the crankcase breather hose is on the inside side of the rear cylinder.I have an 03 vulcan 800A, I know where the crankcase vent line plugs into the airbox, but for the life of me cannot find where the vent hose plugs into the crankcase. Where is the crankcase vent located (the nipple the vent hose plugs into on the crankcase)? I have ridden a few miles now with the vent hose not attached. I thought it was the very small hose that comes out of the case on the left side on the top of the case in between the cylinders. Thanks!
Too much oil in the engine is probably the culprit. I removed all of the EPA stuff and ran a hose from the air breather up, under the seat (over the rear cylinder) down the frame, zip tied to the end of it. I tried putting a filter on the end of it, but that just got dirty so fast and got tired of cleaning it from the oil blow-out. So I just stuck a tube adapter on the end of it to make the hole a little smaller. Oil still drips out, just a little though.I've read a few threads about engine oil blow by into the air filter after doing a search for "air breather hose".
My 1995 VN800A had oil flowing, not just dripping, out the air filter.
The Clymer maintenance manual doesn't have a troubleshooting description for this problem. Though I hate doing it, I've made an assumption... due to lack of actual description in the Clymer manual, the assumption is the "Engine Breather Hose" is related to the "air suction valve".
Excessive oil level seems to be the popular cause.
I'll be draining the oil and refilling with new oil, re-verify oil level, then run the engine to see if this happens again.
The next question is "would a bad air suction valve be the actual culprit?"
What is odd is that before winter layup I didn't have this problem.
I"ll be back to add my result or failure...
I run Yamalube 10W-40 in mine and it still does it.Someone also suggested I run the Kawi oil