Blown Mercruiser 5.0 Alpha. Low hours. Replacement options

[FishStretcher]

My MPI has no return and pump is on the engine. Water separator is on engine, too.

[FLexpat]

The biggest differences I am aware of to watch out for in a motor swap are the new style rear mount bushing and the new style wiring harness on late model MCM motors:

• Mercruiser eliminated the spiral spring in the rear mount bushings in 2003 and changed the height slightly - that means the height of the fwd mts may change a little. Mercruiser service Bulletin 2003-11.
• I can't remember when they went from the 9 pin round harness connector to the 14 pin connector but there adapters for that.

[keith]

Originally Posted by FLexpat

The biggest differences I am aware of to watch out for in a motor swap are the new style rear mount bushing and the new style wiring harness on late model MCM motors:

• Mercruiser eliminated the spiral spring in the rear mount bushings in 2003 and changed the height slightly - that means the height of the fwd mts may change a little. Mercruiser service Bulletin 2003-11.
• I can't remember when they went from the 9 pin round harness connector to the 14 pin connector but there adapters for that.

Thanks for the advice. I currently have the 14 to 9 pin adapter on my motor, which is a 2007. I hope the motor mounts aren't different but I can deal with that when it gets in.

[keith]

Originally Posted by DoozleD

I think i would go with a 5.7. parts are allover the place! one thing to keep in mind is the 5.0 and 5.7 outdrive gear ratios are different so if u go 350 you are going to have to get a 1.47 upper for you drive.

Thanks for this advice! I assume those gears are behind the engine and it is something to replace with the engine out. Is it a pretty simple deal or will I need special tools and skills.

Thanks

[bobbert]

Repowered my 23 with a 357 Mercruiser Reman. Was told by rep they used new blocks and bore over to make it a reman. They also add mechanical fuel pump. Bolted right up to transom ass'y. You would have to check the drive ratio to make sure you have a 1.47 set. The gear set is in the Outdrive.
I am very please with the set up. runs like a scalled cat.
If your interest in a 4.5 FWC MPI new left over call Marine liquidaters in Fort Peirce, they had one there in Feb. for 5500.

[keith]

Thanks Bobbert. The 357 reman is one of the engines I am looking at. It is either that or the 5.7 mpi remanufactured. I guess you had that choice too. How do you like the new motor? Any regrets not going with the MPI?
I have 1.62 gears and have been told that I can re-prop instead of changing them.

[bobbert]

Just LOVE my 357. Gets up and goes, very economical. Picked the carb over MPI because we have big Ethanhol issues. Here it can run 5-14% and really does a number on the MPI.
This 357 is a Mercury motor, not a secondary builder. Hot run test, 2 year warranty, etc.

As far as the drive ratio, I would spring the bucks to change to the 1.47 ratio. You could diddle with the prop but it would be a compromise situation.

Buy the way it was a quick Drop in install.

[FishStretcher]

Originally Posted by bobbert

Just LOVE my 357. Gets up and goes, very economical. Picked the carb over MPI because we have big Ethanhol issues. Here it can run 5-14% and really does a number on the MPI.
This 357 is a Mercury motor, not a secondary builder. Hot run test, 2 year warranty, etc.

As far as the drive ratio, I would spring the bucks to change to the 1.47 ratio. You could diddle with the prop but it would be a compromise situation.

Buy the way it was a quick Drop in install.

Funny, my mechanic recommends MPI over carb for ethanol reasons.

He said you can run a 25 micron separator with MPI, 10 with carb. Who knows?

[keith]

Originally Posted by bobbert

Just LOVE my 357. Gets up and goes, very economical. Picked the carb over MPI because we have big Ethanhol issues. Here it can run 5-14% and really does a number on the MPI.
This 357 is a Mercury motor, not a secondary builder. Hot run test, 2 year warranty, etc.

As far as the drive ratio, I would spring the bucks to change to the 1.47 ratio. You could diddle with the prop but it would be a compromise situation.

Buy the way it was a quick Drop in install.

Thanks for the feedback Bobbert. After a lot of back and forth I went with the MPI motor although I think I would have been happy with the carb too. Did you use riser extensions on your motor exhaust? I am wondering because we couldn't order extensions for my new engine and it will be about 16.5" above water line I think. My current engine is around 18" and the new one is 1.5" lower on the risers.

[FLexpat]

While you have the engine out inspect the bottom of the Y pipe (exhaust) very closely where it bolts to the transom housing - the one I removed from my 23 was corroded very badly and the lower bolts had nothing left to attach to.