repower 2003 rinker 312

monster

2003 twin 5.0 so my starboard engine went filled with h2o  port engine compression engine still ok. one cylinder compression read 130 others on port read 140 and 135 I think brand new compression should be at 175. if you know what compression should be chime in please. starboard transom leaking slightly. port ok. but the boat is raw water cooled and 18 years in salt h20. original aluminum gas tanks. If gas tanks are advised what gas tank would you recommend. do you see where I'm going with this? here is my question and I'm seeking advice.  does mercury repower the 5.0 engine? if not will the 350 be able to mount in my boat in the same place and fit?  also pricing if you know. thank you in advance

PickleRick

Id personally sell the good 5.0 for used and toss in 2 new or reman 5.7s.  Most likely same or better fuel economy plus better perfomance.

Lots of stuff id address while its out. You can keep raw water cooling but id go with closed loop if you can swing it. Hoses, cleaning, easy to access maintenance items to address while motor are out.

Michigan motors has good prices and reputation for motors and I believe you can get them drop in ready with new manifolds, risers and spacers if needed as well as closed or raw water cooled.   

For fuel tank custom made aluminum is most likely in order, rinker is either shutting down or already gone so if great lakes skipper doesn't have n.o.s. then custom will be about the only way i know of to get one.. I used speedy tanks out of NJ and came epoxy coated for a good price. Im on the east coast so shipping was good.   That being said if your tanks have been kept dry and pass a leak down test, no signs or corrosion I'd leave well enough alone and just do the motors and mainance.  

I should also add the compression should be tested warm and all cylinders within 20% or so from each other.  A leak down test is a much better way to test an engine  rings, cylinders and valves.

Things like closed choke, oil in cylinders, variations in cyl temp and battery/starter condion can add to skewed test compression results.

monster

where would I sell my engine and 5.7 will fit in my boat? thank you

Handymans342

A 5.7 is the same block as the 5.0

PickleRick

monster said:

where would I sell my engine and 5.7 will fit in my boat? thank you

Craigslist is where I sold my last one. Take a video of it running, oil pressure and document warm compression numbers.  Winterize and fog before storage as spring and early summer are when they sell here locally.