Help with JD L100. HOPEFULLY :/

Hello all. My father in law was getting ready to trash his JD L100 and I decided to take it. He accidentally used the wrong oil and overfilled it and started it. It started up and oil went everywhere and he shut it down and it hasn't ran right since. So I took the valve cover off lastnight and noticed that the one valve cap came off so I put it back on and adjusted the valves back to specs and it started up and ran and I even got to cut my grass. Well when I was almost finished I noticed it leaking oil. The oil is coming out of the center of the fuel pump from that screen/mesh area of the pump. I looked and the oil level is where it should be. Hooked up my compression tester and it held pressure for an hour so I took it off and put the spark plug back in. Changed the oil to 30wt. Started it up, it ran for about 3-5 minutes and started to sputter and then it died. I crank it back over it started right up and noticed my oil leak. Oil is starting to pour out of the fuel pump. My guess is it was getting oil instead of fuel causing it to stall out. Should I try a new fuel pump? I'm lost on this.

The diaphragm in the pump is probably gone. Replace pump and the short hose that goes Into the valve cover.

There is no hose that goes into the valve cover

Then you don't have a fuel pump? There is 3 lines on a fuel pump. Where is the 3rd hose going if not in the valve cover?

It goes from the pump to the oil fill tube

That's different. I'd replace the hose as well as the pump.

I think I found my issue

I'd say so.

Ok got a new head gasket coming tomorrow. Forgive me for asking this stupid question please. Now is there anyway to tell what stroke it is on with the head off or no? Or do I have to put the head on along with the push rods and tell that way? I'm not real good with being able to tell what stroke it is on and don't want to mess up the valve adjustments.

IT will make no difference as the cam controls the valve timing and the cam is in the bottom of the engine,
You can pop the pushrods back in
The lower one is the inlet & the upper is the exhaust .
Hold them in with your finger so they don't jump off the followers then turn the flywheel and feel which one is moving .
The inlet should open, piston dropping on induction then close near the bottom ( compression ) then bump slightly open just before tdc.
That is compression / firing so a 1/4 " more of piston drop is where you should be setting the valve lash.
Some like to mark the flywheel against a fin ( mark it as well ) to make finding the right spot easier when the head is on but you still will need to find compression stroke.