Author Topic: crankcase vent - mist (Read 3515 times)

bikeb4cage · « **on:** March 23, 2007, 09:39:37 PM »

I have a 2001 Bandit 1200 - stage II jet kit - have noticed before, when the bike is hot, a mist coming from the crankcase vent (located just forward of the valve cover, in stage II mod configuration) - thought this was due to a high oil level. I drained some oil to get the level right, but noticed the mist again (it's an oil mist, at least, I hope it is) today - was 85 F or so, and was in stop and go traffic, so the engine was fairly hot - is this normal? With the airbox installed, you wouldn't see the mist, as it would get pulled into the carbs - so, I am thinking it's normal....
thanks
Jay

Red01 · « **Reply #1 on:** March 24, 2007, 09:57:08 AM »

Yes, it is normal. Do you have a little filter on the end of the breather hose? If not, putting one on will reduce breather emissions considerably. If you do have a filter on the end, it's normal to get a little oil smoke out of the filter, especially in slow or stopped situations.

Some have gone to the length of installing a little breather catch box for oil to settle & collect in, then periodically drain it.

Another option is to run the breather hose into a Y and put fittings on the pod filters to run the breather fumes thru the motor - similar to the way they did from the factory.

ZenMan · « **Reply #2 on:** March 24, 2007, 10:49:33 AM »

You just brought back some road-racing memories... having a "catch box" or bottle was required to pass WERA tech inspection. Thrashing a motor at high revs on the track could produce quite a bit of oil blown out of the vent hose... you don't want that on your rear tire.

A lot of riders got rather creative with what they used for a catch-bottle. It was hilarious to see a sleek race bike with thousands of dollars of high-performance parts in it, immaculately twisted safety wire, and finely fabricated brackets, and then looking closely behind the spotless engine there would be a plastic Flintstones vitamin bottle with the overflow hose wired into it, duct-taped to the frame.

It was easier to just throw it away between races and stick something else on... everything from beer cans to soda bottles.

Bob Holland · « **Reply #3 on:** March 24, 2007, 04:09:07 PM »

I use a Pingel Catch Can on my Bandit, with a hose running out the back. I get almost no blow coming out, but I drain an ounce or two of water, with a little oil emulson, every couple of months.

bikeb4cage · « **Reply #4 on:** March 24, 2007, 07:55:04 PM »

thanks all, yep, do have the little filter on it - think I wil just leave as is and clean the engine periodically - the discharged oil amount has gone down (I think) since I set the oil level correctly - previous owner had overfilled -when I got the bike, there was a lot of oil and dirt around the vent filter (just above the front of the valve cover).
Jay