I bought the boat last fall. The engine was gone thru just before I purchased it. Cast heads were changed to aluminum. Before the overhaul, previous owner always had blow by in the valves and said the engine compartment was always oily. He added a puke tank to try and solve the problem. Still have some blow by and no oil going to the puke tank. Today I noticed what looked like oil coming up the dipstick tube. The engine only runs about 48-4900 rpm with a top speed of 71 with perfect conditions. Previous owner said it ran about 5400 rpm with a top speed of 77. Anybody have any thoughts of what could be going on with my engine?

What hull? Is this a 22 foot boat? That's a stout speed for an HP500EFI single engine boat.
Are you sure the tachometer is right?

288 Sunsation, engine is pushing approximately 560 hp according to previous owner.

To get this out of the way and don't take offense if not, is this your first boat ?

Yes this is my first performance boat. No offense taken, i know some but by no means an expert!

Don't worry, you'll know more than you ever wanted to about oil cooler line sizes, why electric fuel pumps suck in boats, and how replacing a trim tab leads to adding a mega blower to your engine soon enough.

Where do you live? Was it winterized properly? Any water in the oil? The standard brain trust question will be have you done a compression test yet?

A 288 if my memory serves me right ran 72 with a 496 ho
560 should in fact be close to...75-77 like stated.
Did you do a compression test? I would!

Northern MI, it was winterized properly, I have not done a compression test yet. Engine seems to run strong, no misfiring, always starts good, just seems to be lacking something. I'm assuming the stock tach on the dash is correct but could be off a little?

What psi should I be seeing while checking compression?

How much have you played with trim, tabs, and a GPS ?