Oh great gurus of OSO ... Info on 1999 7.4L MPI 310HP Mrec black motors???
#11
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The motors are good as said above. I have heard of many of them losing the electric fuel pumps though. I think Merc had an issue with those. I know a few people who had to replace them due to premature failures.
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Awesome stuff! Thanks to all you gurus
E Coast B. The boat is raw water cooled (strike 1), marina kept in water (stike 2), no rack, lift, trailer kept (strike 2.5 LOL
really same as strike 2), BOTTOM painted
also (strike 2.75). Now, with all of those negatives stated and noted, there's a lot of nice about this boat too
And, if mine (I pledge LOL ), it to be lift kept, bottom paint stripped, possibly converted to closed cooled,,,, or even an eventual engine swap.
We'll see Russ. I'm trying to work a deal ... looking to swap boat for boat straight up
Still a way to go with this motivated seller. I was on the boat yesterday and seemed like everything I'd expect a very well kept 1999 Formula to be. I really like. BUT I reallllly love my Cig Mistress, just that rest of family doesn't :-( It would be another 'sacrafice' for the family, but hey life's tough sometimes! LOL
If it happens it happens if not I'll 'suffer' another year with my Mistress
And the ride offer will always still be open of course!
Later Chris
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E Coast B. The boat is raw water cooled (strike 1), marina kept in water (stike 2), no rack, lift, trailer kept (strike 2.5 LOL
![Stick Out Tongue](/forums/images/smilies/tongue.gif)
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We'll see Russ. I'm trying to work a deal ... looking to swap boat for boat straight up
![EEK!](/forums/images/smilies/eek.gif)
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And the ride offer will always still be open of course!
Later Chris
Last edited by NJgr8ful; 09-15-2005 at 06:25 PM.
#13
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Originally Posted by jaybird
The motors are good as said above. I have heard of many of them losing the electric fuel pumps though. I think Merc had an issue with those. I know a few people who had to replace them due to premature failures.
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I would be more concerned with that many hours in salt on the rest of the system.
I had a 7.4mpi. Very reliable.
The biggest problems that I know and heard about from salt are the corrosion of the exhaust system at the riser, especially. Once this fails, you suck water and poof...
Kent
I had a 7.4mpi. Very reliable.
The biggest problems that I know and heard about from salt are the corrosion of the exhaust system at the riser, especially. Once this fails, you suck water and poof...
Kent
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heres my .02 - Upgrading for power would kinda of be a waste of time with an SS so being cast is no big loss - It is what it is - its not made to go 100mph (ditto on the bottom paint) . 350 hrs in NJ (is that where it is?) isn't like 350 hrs in FL, its was flushed and stored for the winters and not sitting endlessly with salt in it. Is it in a bay or in brackish river water?
Good luck, they're great boats.
Good luck, they're great boats.
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Chris G.
Chris G.
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A couple of things to look out for. First, some of the early 7.4MPI's had ECU problems. I had a cold start problem that turned out to be a bad ECU. Merc replaced it under warranty even though at the time the motor was 4 years old (it was a '99 model and this was in 2003). Another area to look at is the motor mounts. If you see a lot of corrosion on them, then take a flashlight and look at the backside of the exhaust manifolds that face the cylinder heads. Look for the threaded plugs that Merc puts into the casting holes. The early 7.4MPI's had nylon plugs that were prone to leak. On my boat, the water leaked down and pooled on the motor mounts. All in all, it is a decent motor. They have tons of torque, but quickly run out of steam above 4,000 RPM. The intake manifold and throttle body design are pretty restrictive.
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Last summer I bought a 1997 330SS with 7.4 MPI mercruisers with Bravo 3's out of a charity. Boat ran great for the sea trial. Returned home to a bilge full of milkshake the next weekend. The intake manifolds corroded from the inside out in the water passage by the distributor. I got a lot of money back because the charity had performed a shoddy weld repair to one of the motors and denied any knowledge of any history of problems.
For 1997 at least mercruiser used an aluminum intake manifold and no brass or bronze bushing for the water passage. From talking to a couple of mechanics corrosion of the intake is a problem for the early MPI motors and the fuel injection manifolds are not cheap. Because there was evidence of prior water intrusion in the engines when the manifolds were pulled I installed remanufactured carbed motors rather than worry about reliability when I'm 100 miles from home.
If the boat has a windlass, check the mountings for the bow roller. The two forward most bolts were broken on mine and leaked into the cabin. Repairing it was not difficult, but did require removing the windlass for access.
For 1997 at least mercruiser used an aluminum intake manifold and no brass or bronze bushing for the water passage. From talking to a couple of mechanics corrosion of the intake is a problem for the early MPI motors and the fuel injection manifolds are not cheap. Because there was evidence of prior water intrusion in the engines when the manifolds were pulled I installed remanufactured carbed motors rather than worry about reliability when I'm 100 miles from home.
If the boat has a windlass, check the mountings for the bow roller. The two forward most bolts were broken on mine and leaked into the cabin. Repairing it was not difficult, but did require removing the windlass for access.
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Originally Posted by NJgr8ful
Oh forged
I remember reading that somewhere now
Guess you can't Whipple these things?!
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#20
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Yea that is why the boost levels are under 4 lbs on the 496's. They don't respond well to much boost.