Author Topic: Water and Mayo coming out of rear sump  (Read 1184 times)

Offline helipic

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Water and Mayo coming out of rear sump
« on: July 06, 2019, 03:41:44 PM »
Hi all, every time I change oil, I notice water and Mayo from my rear sump.  I don't do short distance rides, mostly 30+ miles per ride at highway speeds.  It seems to me that V7ii uses the frame top tube as crankcase ventilation allowing the water and vapor to return to sump via a one-way valve.  Is anybody experiencing this problem?  I never had  this water issue with my Breva 750. BTW, I don't wash my bike or ride in the rain.  Last oil change was 2000 miles ago.






« Last Edit: July 06, 2019, 03:46:25 PM by helipic »

Offline SmithSwede

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Re: Water and Mayo coming out of rear sump
« Reply #1 on: July 06, 2019, 07:06:36 PM »
Unless your vents have some kind of fault, I don’t think you should worry.  They aren’t vented to the frame.  No design flaw—just an old fashioned, old school air-cooled engine

The engine is just not getting hot enough to burn off the “mayo,” which is an emulsion of engine oil and water vapor. 

Warm it up gently for 8 to 10 miles, and then run it really hard at freeway speeds for 20 or 30 miles.   That process will burn this mayo out.
« Last Edit: July 07, 2019, 02:42:32 PM by SmithSwede »
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Offline RinkRat II

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Re: Water and Mayo coming out of rear sump
« Reply #2 on: July 07, 2019, 01:09:29 PM »
          One major factor in this is where you live. I believe the humidity in your area is above average most of the year due to rain in winter and spring and  natural increase in summer, and it will take more than a 30 minute run to get all the moisture boiled off.  I know you said you don't ride in the rain but you can still have elevated humidity without precip. This bikes oil cooling system may work a little too well compared to your Breva.  My $.02 :grin:

     Paul B :boozing:

  P S  My ducati has to be ridden at least an hour to prevent the Mayo
« Last Edit: July 07, 2019, 01:10:43 PM by RinkRat II »
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