Need some advice and help from the pro's in here;
My Boat has a 97 HP500 Merc in it with 520 ish hours on it. I noticed a couple blue "Puffs" out of the exhaust last year when I started it cold a couple times. Nothing major, and not every time, but enough that I'm concerned that it might be "time" . It also has developed a little valve train noise. I changed the valve springs last year, didn't find any broken ones, and it didn't cure the noise. Lifter maybe?
Other than those issues, it still runs good.
Any one care to take a shot at what it will cost to go through it? Machine work and parts?