Block intake, if stock RV cover find some 1/8th -3/16th flat aluminum, make 2 plates to bolt onto intake, pretty doesn't matter just the bolt hole spacing and find a bicycle inner tube and cut 2 pieces large enough to cover the plates so they will seal. Then repeat for the exhaust ports. glue them on the plates, or 2 sided tape, dog snot, anything. Then cut 2 small versions fo... wait, this is a 720 so no Rave valves. Install spark plugs then use the pulse line for the fuel pump to pressurize. If you have a popoff guage/pump or a real Mityvac, real ones have a pressure port also, put 5-6 lbs in and clamp the pulse line, watch the gauge. I think the typical OK time/lbs is 1 lb in 10 minutes, been awhile and I would look for leaks anyways. Obviously, the slower the bleed down the better. spray Windex, diluted Dawn dish soap etc everywhere, remove stator cover for front main seal, you may be able to check the rear with PTO on using a mirror and light. Anywhere a bolt goes through the cases or head. You might be lucky and it holds longer. Not sure about the oil injection itself but if little bubbles appear in your oil tank it could be the inner crank seals. If it leaks and you don't see any bubbles it may be leaking past the inner mains then past the RV shaft seal. If I missed something one of the others here can fill in or correct this. And was it you that said their plugs were gray? Sounds lean or you use AV fuel if it was you. Good luck and you'll get it dialed in eventually. Lee
