Me and my friend picked up a 99(?) yard machine and replaced the engine on it since the old one would leak all of the oil out. After we did that we notice the hydrostat on it was really loud so we took it off (GIANT PITA) and drained the oil out and did a refill. Took about the expected amount (put in ~2.5qt of 10w30 when 20w50 is spec) and all is fine and dandy, except it’s not. We did the bleed procedure with a drill and refilled with like 1oz of oil, but on the mower it just bogs and doesn’t move. Redid the air bleed with the exception of doing the entire process with the cap off. Made some air moving sounds and it worked fone, took about another oz of oil. Went to turn the tractor on to move it and it’s doing the exact same thing, bogging and not moving at all. Idk what to do besides repeat the air bleed procedure 1000 more times??? Sorry if this is an insane amount of text but the model number is 618-0319 I think