Just picked up the new boat and pondering the old question, which oil to use. Not sure of the specifics of the motor but it is a 540, Brodix intake, canfield heads and CMI exhaust. It has ALOT of power from 4200 rpm to 5400. Motor has about 10 hrs and has Kendall 25-50 in it. Should I stick with this weight or is there a better choice? Or do I switch to synthetic?

Thanks

Mobile 15-50 is a good choice for synthetic. I like Castrol 20-50 for a dino option. This is a topic that has no correct answer, only tons of opinions.

i had canfield's on my 540 used amsoil 20-50 for 200 hours and the heads and valvetrain looked new