Yeah, make sure you NEED a rebuild before you burn up your wallet.

454/330hp motors will go a LONG time if maintained well.

Now, your signature shows a 1994 model year boat. If your motors are 1994 model, they are likely NOT MkIV motors, which were phased out in 1990/1991. Some boats got leftover MkIV's into the 1992 model year, but I've not seen them factory-installed in a 1994.

That doesn't really affect the rebuild cost, though.

MC

Just to start pulling and reinstalling in addition to other labor charges such as refresh rebuild with the existing parts and machine shop charges, IMO your looking at 4K to 5K per motor. But, there are hidden potential expenses like coupler condition, Gimbal bearing condition and shop supplies. Once you have the motors disassembled, there is no telling what the condition of the existing parts are. The charges can really add up quick. Shop estimates are sometimes not even close. For the cost of rebuilding the Merc motors with the same old and tired parts, you may want to find a good performance motor with the latest performance parts.

Check out the folks of Patriot Performance Engines and speak to Chad Bowling
888-462-8276
https://www.patriot-performance.com/
I was told they build performance marine engines and produce their own line in house CNC aluminum cylinder heads.

Messing with the old motors may not be worth the cost??

Why do you need to rebuild? Are they burning oil, loss of power/compression. If running fine, 500 hours is not excessive if oil changes were done consistently. Plenty of motors running to the 900 to 1k hours mark.

If you're heading down to LOTO area, make sure you stop by and see Gene at Lightning Performance. He has done several motors for OSO folks (including mine). He does everything from basic rebuilds to 1500HP+ custom motors (95% of his work is marine motors but he does occassionaly build a beastly street motor). He is very meticuloous and precise about his work and it shows in the quality and reliability of his finished products.

If nothing else, it's worth a phone call to chat with him. He is a straight shooter and will give you some sound advice. From there you can make an informed decision.

Gene - 573-374-7974

i have 4500 in mine and i removed/installed. a local builder did mine top to bottom. we didn't reuse anything but the block. my motor was pretty well hosed, so we did pistons, rods, crank, cam, bearings, top end w/rebuilt 271 heads (found there were peanut port heads on it once we got it apart so rebuilt some cores my builder had). did it with a few mild goodies. pretty much made it ~400hp for a mild, reliable motor.