my oil cap fits snug but when i slam the gas it goes 4 feet in the air is there something going on or bad oil cap
IMO you can't (until laws prohibit

) Have too big enough Breathers on these motors but to blow a breather like you describe suggests alot of crankcase pressure , could be a number of things Tom
Crankcase pressure that is sufficiant to "blow" a valve cover cap is Pure and simple "abnormal" , An N/A Jet boat motor such as this is a 5k + or - rpm motor , as a general rule this type engine should run forever with a PCV valve on one side and a large atmosphere breather on the other or simply two moderate size breathers (one on right and on left) , with little to no "blow by or residue". Blow by from excess crankcase pressure can be resultanat from "mis build" , including but not limited to piston to wall clearance, ring clearance and poor or improper ring seating ,stuck rings , burned piston , etc etc issues. Granted Pan Vac systems and Puke tanks will aid and help "control' or "mask" some of this but they shouldn't be neccesary as a rule . I would do a wet and dry compression test and cylinder leakdown myself Just my 02 Tom