Flushing crankcase of old oil during change, on softails

I flush it. I use a piece of cardboard (filter box) tucked up under the oil filter mount. using a measuring cup I run the motor till I have drained 2 cups from the motor. I then install the filter prefilled, add 2 cups of oil to the oil bag start the engine, run for a minute, then top off the oil level if necessary. This is done after I have drained and refilled the oil bag with fresh oil. This process works on EVOs. Do not do this on a twin cam. You will do major damage to your engine.

I just ride till the oil is hot and change it. Most people dump more dirt in their oil using a funnel wiped out with a rag. Not going to worry about a couple oz.s of yucky oil.

I had the same concern about the old oil left in my super glide. Found this oil change system in Bagger magazine. Its called the Scavenger. Go to www.roguechopper.com. They have videos of how the system works. I bought it and it works great. Now your oil looks like you changed it after you changed it.

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leeanders said:

Just curious, I'll be changing the fluids for the first time in my FLSTF, before long. I've read that once the oil tank is completely drained and the oil filter is removed, there remains at least 14 to 16 ozs of old oil in the crank.

How many of you flush out that oil? Or is it routine to just refill the oil tank and allow the old stuff to mix in with the new oil?

If you flush it out, what process do you use?

Will appreciate any information on this subject.

Thanks.

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That's too much oil in the case....4-6 oz is normal...if there's 14-16 ozs you're sumping and have a scavenging problem...

The only reason that I can see for doing it would be if the oil was contaminated with something or had been sitting in the crankcase for a long, long time.

You can do it on a softail by pulling loose the return line and draining the oil out using a piece of hose to extend the line. The return line is the outer line going to the oil bag. But, as I said, I don't see the point in doing it unless you have a specific reason.


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add some seafoam motor treatment to the crankcase about 20 mi before you change it.

chasarms said:

The only reason that I can see for doing it would be if the oil was contaminated with something or had been sitting in the crankcase for a long, long time.

You can do it on a softail by pulling loose the return line and draining the oil out there using a piece of those. The return line is the outer line going to the oil bag. But, as I said, I don't see the point in doing it unless you have a specific reason.


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:thumbsup. I agree...I did it on my Evo once and as simple as it is on the Evo's(just leave the filter off) it wasn't worth the effort for the 1/2 cup of old oil that came out,before it turned clean...

chasarms said:

The only reason that I can see for doing it would be if the oil was contaminated with something or had been sitting in the crankcase for a long, long time.

You can do it on a softail by pulling loose the return line and draining the oil out using a piece of hose to extend the line. The return line is the outer line going to the oil bag. But, as I said, I don't see the point in doing it unless you have a specific reason.


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The oil return line at the oil bucket goes to the oil filter, so disconnecting it and using it to drain the crankcase is a waste of time. It is a big problem that Harley didn’t put in a crankcase oil drain ….you can’t drain the oil when the engine wet sumps and you can’t get the last of the oil out when doing an oil change. The only way to drain the crank for these reasons is to remove the upper crankcase inspection hole….the place you use to look at the flywheel timing marks and thread a small plastic hose from here down into the bottom of the crank. you then suck the oil out using a small scavenger pump or lift the bike off the ground,(I use my Handy Lift) and siphon it out.

10 year old thread...