sea.hart561

I have a 86 checkmate convincor that needs a new motor. I found a 1998 502 mercruiser with 750 hours on it it has redone heads and the fuel injectors were just gone through. They are asking for 5,500 installed plus my old junk motor with the stainless exhaust manifold and gil exhaust. any feed back on the lifetime of these motors and things to look for would be great
thanks
Chris

mikebrls

seem's like a lot of hour's if it was in a performance boat

cigrocket

iTrader: (3)

I think you can do better for same $. Only 400-500 to install a motor

rak rua

The two posts above suggest it's not cheap. There's a couple of 496's on here. I know they're asking twice as much money and you'll probably still need exhaust but....... Might not hurt to contact them, may be negotiable and you get a later model engine with 200 hours and your old engine (you say it's junk) may cover installation costs or help with exhaust?

Just a thought, don't know about geography and freight, they may be sold already anyway.

http://www.offshoreonly.com/classifi...ne-o64711.html

http://www.offshoreonly.com/forums/s...96-ho-mag.html

RR

mike tkach

iTrader: (3)

502 lifetime=751 hours!just kidding but plan a rebuild in the budget.that is a lot of hours.

glassdave

iTrader: (1)

try to hang onto your exhaust or at the very least make sure the trade is a lateral move and not backwards to some old cast iron stuff. I'm assuming your going from a carb setup to a FI setup and sounds like they are doing the install? That being said dollar amount isnt horrible but not great either and the hours would still make me a bit nervous unless you cam get some history on it. Those things are fully capable of seven fifty no prob but certain criteria need to be met(verified) along the way and even if it runs like a top the clock it still tickin and full rebuild is right around the corner (the fresh top end will buy some time). Could use a little more info on the deal. Are you basically dropping off the boat and picking up a done running piece? I also assume they will be adding the proper fuel system of the FI. Going from a carb to a Mag EFI is a great step up here to . . .

sea.hart561

I would be dropping the boat off and picking it up running with a sea trial. The exhaust and manifold are stock mercruiser on the 502 and the ones I would be trading in are gil stainless with stainless marine manifolds along with a 454 block and the rest of the pieces in boxes and crates. The story They gave me is that they sold it as a crate motor to a guy with another checkmate and serviced it from 500hrs till now. The checkmate had destroyed its hull and they parted out the boat. Its the 502 mag mpi if that makes any difference. With all that work done on the top end would it be safe to say that if compression and oil pressure check out its in good shape? what exactly is a motor refresh and cost of one? When I bought the boat it had a 454 I went for a test ride, did compression, checked the oil and the motor blew up about 5 hrs later the scumbag got me. The crank was scored about a 1/16 of an inch so I am very nervous about my next motor purchase. The 502 is coming from reputable powerboat boat shop and a 502 in a convinvor sounds like a nice setup.
Thanks again for all the help

rak rua

I reckon lots of members here know more than I do when it comes to longevity and ease of maintenance on a 502. That said, I think I would be trying to find something with lower hours. The engine may be great but you can't deny the hours and the age. I would be worried you may be back here in 2 years with the same question.

You've had one bad experience (sorry mate, can happen to anyone) and I'd hate you to get stuck in that chit again. How many hours on your old engine? Is it a lot more than 750?

As I said, I'm less knowledgeable than many here so it's just my opinion. You can all shoot me down now if you disagree, I've learnt a lot from OSO and enjoy learning more!

RR

Griff

This makes no sense Gil and SM will not fit each other.

Griff

The engine was fine for 5 hrs and showed no signs of a problem prior to purchase. Chit breaks.
I had a drive let loose 5 hrs after I bought a boat. I test drove it for an hour prior. No sign of an issue. Chit breaks

You should be somewhat nervous, especially if looking at 750hr engine. Then again, it might be fine for another 500 hrs.