Need motor-sport jet 90

[backwater dawg]

Now here's the BAD news--1994 merc sport jet 90 motor has cracked sleaves-egg shaped cyls-chewed up center piston--ect-ect-ect---the big question is?? The best soulution I think is to get a reman block?? any ideas as to where is the best (cheapest)
place to look---and is there any other motor options that as long as I need to replace the engine that I should consider??? Thanks Steve

 

[Don S]

Re: Need motor-sport jet 90

The Sportsjet 90 used a Force OB powerhead, so will move this over to the Force forum.

 

[Frank Acampora]

Re: Need motor-sport jet 90

Last jet I saw was a Sea Raider and it had a Force 120 block mounted vertically in it. The question is this: Are all the sleeves actually cracked? --or just scored? And are they too bad to re-sleeve? Aftermarket sleeves are sold, however, they are expensive to install and just any machine shop is not capable of doing that type work. Melted pistons and scored or egg-shaped cylinders are not a death sentence. They only require overboring. Usually .030 over

So, you also have the option of buying a short block to put back in, or you could buy a 120 4 cyl long block to install. Remanufactured blocks cost around 15-1800 bucks without installation. You would be better off money wise to buy a running outboard and use the engine from that. Only thing to be cautious about: Merc changed the splines in the crank sometime in the '90s so be sure you get an engine with the correct number of splines for your application. If your crank is good, you could put it into any 3 cyl block because the block, pistons, and rods were never changed--only the crank splines so they could use a Mercury drive shaft.

Does that help you some?