Air Filter Blow By......I'm Not Immune!!!
Copied from the link posted above-
Correct viscosity is one that gets ignored a lot. 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.
Correct viscosity is one that gets ignored a lot. 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.
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DKCustomProducts.com
DKCustomProducts.com
With the right level of oil and the right viscosity of oil for the temps you start and ride the bike in, the most you should get is a light film on the backplate, and that, only when you run it hard and long.
For 60* and above it is straight 50 weight and for 80* and above it is straight 60 weight.
Not 20-50 or 20-60.
The only time HD recommend a multi-viscosity (20-50) is when the riding temps are under 60*.
Not 20-50 or 20-60.
The only time HD recommend a multi-viscosity (20-50) is when the riding temps are under 60*.
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Joined: Mar 2010
Posts: 38,415
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From: Honah Lee
Just wipe the drool off the old girl's chin..no big deal, they all do it and with the open box air filter show it more. No were to catch any. The longer you let it set now between rides the worst it will appear since it has time to runs down out of the vent pluming. 3 drips looks like a quart after 70 mph.
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Road Master
Joined: Jul 2011
Posts: 1,030
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From: Calgary AB
The blow by on my '06 was getting really bad. I finally replaced the breather filters. That made a huge difference. Now instead of drips I get mist, but only noticeable at extended highway runs (at about 3500 RPM). Which I consider normal. I don't know how often the filters should be changed, I think mine started becoming a problem at 10K or 15K miles.
I plumbed it into a little Kuryakyn catch can. Now it's staying nice and clean.
I plumbed it into a little Kuryakyn catch can. Now it's staying nice and clean.
Last edited by dwagar; Sep 1, 2012 at 10:59 AM.
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