The RK does have an oil tank, located under the transmission...

And, the oil could also go into the crank case. It's a guess until somebody pulls the derby cover (have oil catching pan ready below), or the crank case plug.

 

Just pulled primary inspection cover,it's fine,oil level just below the lip.

 

Case plug next

 

If i understandcorrectly, you have changed the oil and added 4 Qts of oil. Everything was fine before the oil change. You rode 20 miles and the oil light came on so you added a Qt. You now have 5 Qts of oil in your system and can't see it on the dipstick and have no signs of leaking. The crack seal is not leaking as the primary level is normal.

So where has 5 Qts of oil went?

Snap a pushrod cover off and see if the rocker boxes unload the lost oil....

 

Sumping, oil pump not returning

 

check ball stuck

 

So how does a check ball get stuck or the oil pump lose prime during an oil change?

 

Had the same issue on my 07 CVO RK. Oil pump is sumping or simply not working. And it happened less than 20 miles after a oil change.

 

Case plug out,maybe 3 ounces,cant measure it.Pushrod covers next.

 

There really isn't anywhere a gallon of oil can hide? Check the trans and primary but I'd say ya got a scavenge pump/pick-up problem if oil isn't getting back to the tank. Pull the engine drain and see what comes out? I bet it and the primary are really full. My guess is a bad filter. First, I'd replace it and see what happens??