We all have to go thru the process of elimination and lowering the oil level rarely has an effect on it...I run mine right on the full mark and let the 'plumbing' do the rest. Do what you think is best.

 

I suppose, but a longer con rod, would still attach to the crank in the same fashion as any other. And i would assume the overall diameter of the flywheels is the same, so there really shouldnt be any difference in the "crankcase turbulance" right? Just tryin to get this whole idea. Either way im glad its not an issue im facing, not to rub it in.

 

Ur missing the point, the air is being moved by the piston and NOT the rods, crank, etc. Just like the top sides of the pistons are moving 96/103 cubic inches of air... so is the underneath side of the pistons... they ALSO are moving more air. Breathing on an engine is a matter of the air the UNDERSIDE of the pistons. On top... you got suck, bang, blow, underneath it is STILL suck and blow.

 

Yes i understand, I was just under the assumption that the oil mist, was caused by the crank and flywheels whipping in the oil in the crankcase. And then depending on how much air is being forced back downward under the piston, will determine how much air is being vented, and carrying the oil mist out with it.

K, think I figured it out as I went along!

 

Quite right! The extreme example is a flat twin like a BMW. While their cylinders shift say 1200cc of air every two crankshaft revolutions, the crankcase shifts that amount every revolution. So a flat twin moves twice as much air through it's crankcases as through its combustion chambers. Our V-twins move much less, but it is still significant.

 

does it smell like gasoline ?

If so, it could be reversion.

which can be tuned out by a change to the exhaust tract.

Mike

 

Basically your bike is venting too much oil mist at sustained high rpm than it is able to suck into the air intake venting to burn off in the engine. It can be due to a bunch of different things, have your mechanic check to make sure your oil pump is not misaligned, or you have a bad o-ring at one of the fittings in your venting system. Harley has used different methods over the years, bikes since 2007 should not require jury rigging the venting system, there is a malfunction somewhere that is showing up due to oil mist accumulating at the rpm's you are riding at for long periods of time. A buddy had the same exact issue as yours with a HD heavy breather spitting oil and it turned out to be a damaged $2 o-ring at the back plate fitting.

 

While two big pistons moving up and down at about the same time do present major "breathing" problems, Oil misting is actually not as big a problem as these threads lead everyone to believe. The Harley breather system works pretty good. If ya are having misting trouble something in the system is messed up. Usually the valves in the rocker box, a blocked passage or a leak. Oil sumping is another problem but still a cause. There are tons of bikes out there with no problem with misting.

 

HD knows all this, that is one of the reasons you will find the following in your manual about oil level and oil viscosity-

https://www.hdforums.com/forum/oil-r...oil-level.html

"The correct oil level should register midway between the FULL and ADD marks on the dipstick.

If oil level is at or below the ADD mark, add only enough oil to bring the level to the middle of the two marks on the dipstick."


The manual states that the recommended viscosity is SAE 50 if the lowest ambient temps are above 60* and SAE 60 if the lowest ambient temps are above 80*.

However, most people (and Harley Dealerships) are running 20-50 year round, then they wonder why in the middle of summer when temps are 75-100* (like they are in our area) they hear more top end noise and get so much blow-by.

 

Did this all start about the same time you cleaned and re-oiled your filter? If so use less oil on filter.