New guy
 

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 :D

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. :picard1:

Ok so I need to get a filter with the anti drain back valve. I was gonna get mobile 1 m1-302a I read people have good luck with them. And that makes since checking in the water. I guess I’ll suck a couple quarts out bring some fresh oil to the lake with me. Thanks guys for all the help.

Welcome

I've used the Mobil 1 M1 302's (302a now) for 20+ years

Sorry if I’m alll over the place but now prop questions , do I actually lose efficiency being under propped? I believe I am. At 62-63 on gps I was bouncing off the limiter at 5200. It has got a 23 mirage prop on it. How bad would it hurt time to plane if I went more prop?

Congrats on the new ride! I would leave the prop as is until you get more seat time and experience different conditions w/ the boat. If the prop performs well all around now it’s a winner. Trying to chase a few mph w/ a prop can be like chasing your tail. If you’re bouncing off the rev limiter at WOT w/ just yourself in the boat I’d imagine you won’t w/ a few friends or less than ideal conditions. Buy a new prop when you throw some more power at the motor🍻

Thanks, it’s definitely been fun. Yea I agree some seat time will be beneficial. That was in less than ideal conditions would never of thought about taking the jet boat out in the rough waters like this. But this boat just ate them waves up. It was me and a buddy I’d say a couple hundred pounds each and half tank of fuel. I just don’t want my buddy in his h2x Baja with 454 mag mpi to walk away from me lol.

Well anyone know an alternative m1302 oil filter? Drained oil and took filter off, looks like it’s too long hits exhaust manifold. Need a short one.

I d prob just run a Merc one then

Thanks, that is exactly what I ended up doing. Now unfortunately I’ve been told by a guy at the lake my coupler is bad. Almost like a stall converter. Rpm’s jump real fast then grabs and goes. If I can figure out I can upload a video

Guy at your lake is wrong. That's the opposite of what a bad coupler does. Sounds to me like your prop is blowing out when you are giving it throttle to come up on plane.

BTW, it sounds like your oil filter is mounted with the threads on the top. If that's the case, an anti drain back valve is not needed.