[Philscbx]

Like draining the the last guys bath water -
Would filling back up and having the worst left behind mixed in make you feel ok sitting in it?

If oil chg not done hot off the road - and worst of last drop not pushed out with fresh oil -
Fill in the blanks anyway you like of what's allowed- mixed back in with new oil.

I don't allow lawnmower any less attention.

 

[Philscbx]

It doesn't need a second flush -

When it's hot - pull stick - and grab whiff from crankcase vapor -
Leave the Stick out - come back later to see if it's just normal combustion smell.

Put oil on finger from stick - get a good whiff-

Now open oil can - it came from - sample the smell closely.

 

[Philscbx]

When I was young and beginning to ride bikes dad said:
"when changing the oil you let it run for 5 minutes and let it sit for 3 minutes and then change the oil.

On these - no less than 1/2 hr running total time -

shutting down after the first 15 -
Let heat soak for 20 min - The heat from jugs will slowly transfer into the case.
Then run again - till fan comes on -

Then dump with little delay as possible. Anything that wants to settle out to bottom -
you want it out on the fly. Not attach itself in the bottom.

A typical run up for 12 min and shut down - the jugs are toasty -
the crankcase, 4 qts of oil, & 300lb of iron is still ice cold.

What settled out last night will not move till fully heat soaked and in flight mixed in.

When Oil is at last few drops in the pan - Add in a spill of fresh oil pushes out all of the old of what's waiting.
You can see the color change of new oil come out.

The filter doesn't matter when he's removed - might as well button up the bottom of both plugs -

Dump out that oil so it's empty for the filter , so much less risk & mess if filter flops into hot oil.

If wanting even less mess - just loosen filter a few turn and let 90% empty into pan - while filling the engine with oil.
Don't worry - there's no direct path for oil to exit filter housing with engine off.
On any engine.

Now there should not be one drop of oil on the floor.
It's all about Win/win.