Hi Chopperjoe,
Gaskets are on the way! The oil should be mostly clear after only 20 miles. Sounds like there is still a lot of carbon build up on the piston [ring glands] and I would leave Rislone in and change after 50 miles.
Several items can cause it to start hard after it is warm. Valves, worn rings [or massive carbon build up on the piston], carburetor and lastly ignition. The magneto, when hot, may not fire as well. Points can and should be replaced with the ignition module, and if using the module the condenser must be unhooked. If the points are burned on the contact surface replace the condenser. Make sure the magneto is .010" from the flywheel magnets [use a feeler guage to set]. If the valves are leaking it makes it harder to start when hot. Also check the lifter clearance because valves grow when hot. Set the clearance at .012" on both to make sure the problem isn't valve clearance.
Which spark plug are you using? The "H" with the stock head is a short reach plug [3/8"], and the Hi fin head uses a 1/2" reach plug. If the wrong plug is used it can cause it to start hard when hot if the longer reach version is used. I use Autolite #303 or NGK B6S in the "H" & "J" motors, and NGK B5HS or Champion L90C in the "300" or later motors.
Jetting on the carburetor sounds close to correct.
Have fun,