Open Breather Problem ...
Extreme HDF Member
Joined: Jun 2011
Posts: 10,216
Likes: 224
From: Glendale AZ
will try to lower the oil level 1/2 quart 1st and then will see what happens. the thing that I'm doing is to top off the oil to it's fill level after each and every ride. I think this the problem. I'm running SE oil which supposed to be lighter than the normal HD oil. thanks again.
Road Master
Joined: Jul 2011
Posts: 1,230
Likes: 2
From: Niagara, Ontario, Canada
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.
Outstanding HDF Member
Joined: May 2008
Posts: 2,543
Likes: 19
From: Ashland Ohio
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.
Road Master
Joined: Jul 2011
Posts: 1,230
Likes: 2
From: Niagara, Ontario, Canada
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!
K, think I figured it out as I went along!
Club Member
Joined: Jun 2007
Posts: 45,429
Likes: 2,898
From: Bedford UK
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.
Extreme HDF Member
Joined: Sep 2010
Posts: 14,744
Likes: 402
From: Phoenix '53, '88, '09 Big Twins
If so, it could be reversion.
which can be tuned out by a change to the exhaust tract.
Mike
Seasoned HDF Member
Joined: Jan 2007
Posts: 5,603
Likes: 4,044
From: Virginia
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.
Ultimate HDF Member
Joined: Mar 2012
Posts: 6,129
Likes: 143
From: Santa Cruz
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 Forum Stories
The Best of Harley-Davidson for Lifelong Riders
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Verdad Gallardo
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
10 Motorcycles You Should Never Buy
Joe Kucinski
10 Things Harley-Davidson Needs to Fix in 2026
Verdad Gallardo
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.
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.
__________________
DKCustomProducts.com
DKCustomProducts.com
Thread
Thread Starter
Forum
Replies
Last Post
Twisted Cherry RGU
General Harley Davidson Chat
13
Apr 9, 2017 10:03 AM