Hey all newbie here no real forum experience so help me out if I’m doing this wrong please. So I purchased my first “powerboat” yesterday 1997 VIP vindicator 24ft. Was told it had 502 mag in it. It has the mag intake but there’s no sticker on it. Had it out today for the first time hit 65 on speedo which I know is probably off at 5200 rpm. It seemed great and everything worked. First boat my trim gauge actually worked on lol. My question is about the induction setup I looked the serial number up 0d830050 and it brings up 92-93 502 mag. Would that have been a lower powered carb mag and someone put the 454 mag induction that was original to the boat? If it is running a 454 mag map is that bad?

Welcome to OSO. You're doing it right

Did you have a Merc dealer run the serial number?? That is really the only way to determine what you have. Is the serial number you're seeing on a tag near the starter??

You can also try doing a google search with the engine block casting number.

The tag above the starter.

I looked the serial number up online on a mercruiser parts website

Also kinda needing help understanding this fuel system, as I think I have what’s called VST system. Is this system ran by a mechanical fuel pump that I have to check the oil on? This boat stuff is way more complex than automotive stuff in use to.

That just tell you a range of serial numbers for when you are looking up parts. That same range of serial numbers is used for all kinds of engines made in the same time period. It needs to be run through a Merc dealer to find out exactly what it is. Like I said, also run the engine block casting number. There is no telling what has been changed in 26 years.

VST would be correct for 1996-1997. Mechanical fuel pump is mounted on the sea water pump and is sealed. It uses Merc HP outdrive gear lube in it. The lube gets fuel contaminated and it should be changed every couple years. Change the sea pump impeller at the same time. The VST also has an electric fuel pump

Thanks for the help, this is my first big boat with fuel injected mercruiser, grew up on old jet boats my whole life. So I’m just trying to see what I need to check to make sure it’s as dependable as can be on the lake. There’s a boat dealer down the road I’ll see if they can run the serial number for me. Something strange happened tho I knew the boat was about a quart and a half low when I first saw the boat, but I had read up where 502 mags like yo use oil so I wasn’t too concerned. Put about a quart and a half of oil in it took it out for first time. The next day I checked the oil and I’m about a quart and a half over full? Anybody know how I screwed up checking the oil? I checked it the same place where I keep the the boat so it should be at the same level.

Can you get me the serial number? I'll see if I can help.

For the most accurate reading, oil level needs to be checked when the boat is at rest in the water.
When i first got my boat, the prior owner was using an oil filter that did not have an internal anti drainback valve and oil level varied a lot.

From his first post 0d830050

Sorry… coffee hadn’t quite kicked in yet.