Flushing the engine out
Club Member
Joined: Jun 2007
Posts: 45,429
Likes: 2,897
From: Bedford UK
We have access to a great deal of things these days that wasn't available when I started riding over 40 years ago. Multi-grade oils is one of them, cartridge oil filters is another. Our Harleys are designed to superior levels of quality, made of finer grade materials, machined to much closer degrees of accuracy since those two were introduced. We are spoiling them rotten just putting in modern oils! Let's not go over board.
Last edited by grbrown; Jul 28, 2012 at 03:51 PM. Reason: Expanded.
Seasoned HDF Member
Joined: Dec 2010
Posts: 7,736
Likes: 1,524
From: Coromandel Peninsula New Zealand
There are many reasons not to flush a 50 K motor that has never been flushed before....it can dislodge gunk that can block oil lines and oil ways......seen it happen a few times.
Club Member
Joined: Apr 2011
Posts: 5,776
Likes: 7,811
From: SE Louisiana
My oil is so clean after a oil change, for the first 300 miles or so I have to lay the stick on a paper towel to see where the level is.
It's still pretty clean when I change it at 3500-4000 miles.
I get a additional pint or more of old oil out after I fill my tank with new oil, and not with that scavenger thingy.
Very Simple, the filter on a Evo is on the return to the tank.
Cut the very bottom off a used filter, screw it on,
hold a funnel or plastic soda bottle with the bottom cut out, up to the cut off end of the filter to catch oil(horizontal filter on my '97 softail),
on my '90 ultra the filter is under the bike, just place a pan under the filter.
the cut filter is just to not make a mess, even though the return oil is under very little pressure because there's no restriction in the line.
After filling oil tank, start the engine and watch the oil coming out, when it gets clean, stop engine, put your new filter on, top off oil tank, run engine till warm, check oil level, done.
No damage to bearings or lifters as there is normal oil pressure(I used to watch the gauge just to make sure), as the filter is on the return to the tank.
Just don't run too much oil out the tank, usually clears after a little more than a pint.
The oil in the softail I bought a few weeks ago was very black, I cycled an extra quart through it to clean it up, it's much better now and still clear after a couple hundred miles.
It's still pretty clean when I change it at 3500-4000 miles.
I get a additional pint or more of old oil out after I fill my tank with new oil, and not with that scavenger thingy.
Very Simple, the filter on a Evo is on the return to the tank.
Cut the very bottom off a used filter, screw it on,
hold a funnel or plastic soda bottle with the bottom cut out, up to the cut off end of the filter to catch oil(horizontal filter on my '97 softail),
on my '90 ultra the filter is under the bike, just place a pan under the filter.
the cut filter is just to not make a mess, even though the return oil is under very little pressure because there's no restriction in the line.
After filling oil tank, start the engine and watch the oil coming out, when it gets clean, stop engine, put your new filter on, top off oil tank, run engine till warm, check oil level, done.
No damage to bearings or lifters as there is normal oil pressure(I used to watch the gauge just to make sure), as the filter is on the return to the tank.
Just don't run too much oil out the tank, usually clears after a little more than a pint.
The oil in the softail I bought a few weeks ago was very black, I cycled an extra quart through it to clean it up, it's much better now and still clear after a couple hundred miles.
Last edited by Schex; Jul 29, 2012 at 01:16 AM.
Road Warrior
Joined: Apr 2007
Posts: 1,952
Likes: 15
From: Senoia, Ga., by way of Miami, Fl..
I completely understnad the opinion that it is not necessary. However, I fail to see why so many are SO adamantly against it.. It is NOT a flush! It is simply a complete oil change.. It wont losen up anything that the regular oil change doesnt, it simply removes all of the old oil... I have yet to do it, but how can it possibly be a bad thing?? Anytime you can get ALL the **** out of your engine, its a good thing.. Todays oil is far better than in the past and change intervals are not so much for oil breakdown, its more about getting the suspended trash out of it, stuff the filter cannot remove, the BLACK stuff. This is the primary reason I do not belive in synthetic's in general..
Seasoned HDF Member
Joined: Aug 2010
Posts: 5,173
Likes: 177
From: East Coast
I use the Scavenger also. Its merits are quite apparent. Is it necessary? Of course not. However, I'd like to have someone explain how having absolutely immaculate oil can harm anything, especially for the HUGE financial outlay of $60.
So far, this enormous expense has cost me about $15 more an oil change, or just a tad more than ONE QUART of synthetic oil. In 4 more oil changes, that becomes $7.50 per oil change and so on. Very soon, it will be adding the cost of a small coffee to the oil change. Wow, do we love to throw our money away or what?
So far, this enormous expense has cost me about $15 more an oil change, or just a tad more than ONE QUART of synthetic oil. In 4 more oil changes, that becomes $7.50 per oil change and so on. Very soon, it will be adding the cost of a small coffee to the oil change. Wow, do we love to throw our money away or what?
Dirt don't hurt
Joined: Jan 2011
Posts: 21,062
Likes: 4,547
From: Haslet Texas
I use the Scavenger also. Its merits are quite apparent. Is it necessary? Of course not. However, I'd like to have someone explain how having absolutely immaculate oil can harm anything, especially for the HUGE financial outlay of $60.
So far, this enormous expense has cost me about $15 more an oil change, or just a tad more than ONE QUART of synthetic oil. In 4 more oil changes, that becomes $7.50 per oil change and so on. Very soon, it will be adding the cost of a small coffee to the oil change. Wow, do we love to throw our money away or what?
So far, this enormous expense has cost me about $15 more an oil change, or just a tad more than ONE QUART of synthetic oil. In 4 more oil changes, that becomes $7.50 per oil change and so on. Very soon, it will be adding the cost of a small coffee to the oil change. Wow, do we love to throw our money away or what?
Club Member
Joined: Apr 2011
Posts: 5,776
Likes: 7,811
From: SE Louisiana
I rather not fight oil lines in tight spots, make oily mess, and possibly damage the oil line.
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
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
Southpaw Super Glide: A Left-Hand-Drive 1979 Harley FXE Built to Fit the Rider
Verdad Gallardo
Road Captain
Joined: May 2011
Posts: 684
Likes: 9
From: Indian Head, PA
+1 The return to the oil tank is kind of difficult to reach, at least on my bike, and the easiest way to reach it is to remove the tank mounting bolts and pull the tank away from the frame a little. Of course that requires pulling the battery, the upper trim and moving a wire harness. Schex3x's method sounds very quick and easy. When my next change comes up, I plan to implement his method.
Road Master
Joined: Apr 2009
Posts: 1,123
Likes: 43
From: NJ
For me, there is a big difference between flushing a motor and scavenging the oil from one. A motor gets flushed when one adds some kerosene or a store-bought flush and runs it to get the sludge loose. What has been described here is scavenging and I can't see it doing any harm if done properly. I would not mess with the oil lines because that is a good way to induce a leak, the puck or cut off oil filter are ok.
Personally, I change it every 3K and try to stay away from the stator plug-(wiggle it around enough and you will have a leak)- when removing the filter so I don't bother trying to catch the oil from the old filter or scavenge the engine. Been working like this for years..
Ds
Personally, I change it every 3K and try to stay away from the stator plug-(wiggle it around enough and you will have a leak)- when removing the filter so I don't bother trying to catch the oil from the old filter or scavenge the engine. Been working like this for years..
Ds