mercury sport jet

[gator79]

i was just given a bayliner jazz jet boat . the motor is a mercury sport jet 90 hp. it was left outside and the engine compartment filled with rainwater. the motor is currently submerged but you can still turn the crank by hand. it is not locked up. what would be best for this motor besides trashing it? drain water then fill cylinders with oil? I have a force 85 hp outboard that runs, someone said they may be the same powerhead is this true? the boat is a 93 model and the outboard is are 86 ( I think ) model. I would like to fix it up for the kids if it is not to expensive. I am a auto tech so any engine work will not be a problem. thanks

 

[WillyBWright]

Re: mercury sport jet

Yank the plugs ASAP and wing it over til the water stops spraying out. Then squirt a bunch of WD-40 in the holes. Wing that over til it stops spraying out. For that you should have the lanyard removed from the dead-man switch.<br /><br />Charge the battery because it's pretty tired by now and drain the carbs. Put a rag under to soak up the gas or whatever comes out. Throw everything back together and see if you can get it to start. You won't need water if you only run it til it clears out.<br /><br />Assuming you're lucky enough to get it started (you probably will), shoot some 2-stroke oil in there and yank the starter. Take it apart and clean it good. Put it back together and back on. Next, remove the starter solenoid and chuck it. Install the new one you bought because you were really smart and asked about this on iboats.<br /><br />You might consider a new battery. Otherwise let the motor get some direct sun to dry it out and you should be about good to go. Once you get going, the rest will steam off. Just don't be too embarrased when you walk around with a wet beehind from the soaked seats cuz you just got out of your new Jazz at the pier at the Lakeside Bar and Grill. Life is good!<br /><br />You'll want to get a new bilge blower, so see if it's a 3" or 4" and start shopping. I'm sure there'll be a few goodies you'll be wanting anyhow.<br /><br />Happy Boating!

 

[kenimpzoom]

Re: mercury sport jet

Dont know about the 86 Force fitting. The Sport Jet 90s are Force powerheads with Mercury ignition.<br /><br />If it doesnt have spark, check on my home page (icon above) for diagnostics.<br />P.S. These boats will only get about 30-35 mph. If the flotation is water logged it will be less.<br /><br />Ken

 

[WillyBWright]

Re: mercury sport jet

Crank splines are different. Outboard powerheads won't fit SportJets because of that. At least not with the 90s and 120s. Not sure about the V-6s. Come to think of it the SportJet splines are Merc splines, not Chrysler splines. (Not that you're going to get a V-6 on that. Wouldn't that be scarey!)

 

[gator79]

Re: mercury sport jet

can you start this engine on a hose? what about the waterpump impeller? what about the jet drive?

 

[WillyBWright]

Re: mercury sport jet

The cooling water is supplied by the jet impeller. No rubber impeller to burn out. You can run it for up to three minutes. Don't go by feel if it's getting hot. The part that gets hot is inside.

 

[funpilot]

Re: mercury sport jet

With all due respect to Willy, DON'T run your motor without cooling water. You can make an adapter from a hose fitting and a flared fitting (both available from Home Depot, or ACE hardware) that screw together to go on the rubber hose by the exhaust elbow at the stern of the engine, and will enable to you provide a medium flow of water to your engine. Don't exceed about 2000 rpm.<br /><br />Your Sport Jet engine has a lot of space to build up exhaust and unburned fuel in the area next to the impeller. The resulting backfire can Sneeze off your ride plate, disrupting the seal between the jet pump and the ride plate, rendering the jet pump feeble and reducing you to cruising the lake at 10 mph. (edit: the water introduced by the hose flows through the engine and out the exhaust, carrying the unburned gasses with it) Getting the 'sneezed parts straight and back together is tedious, requires a new gasket ($56) and a lot of muscle. The adapter can be made for under $4. I really liked all of his other suggestions though! And Ken has saved me hours of hassle with his excellent trouble shooting guide.<br /><br />Incidentally, the 90hp pump is geared at 1.14:1. The 120 is geared at 1:1.<br /><br />Good luck!

 

[WillyBWright]

Re: mercury sport jet

I thought the gasket was NLA. Seen most Ultra Siliconed. I neglected to mention the gearlube. There are two plugs in front of the intake grate. The one on the middle is the drain, the one on the side is the vent. There's also some lube in the cone you see from the back. You have to take the nozzle off to get at it, but it's not much of a job. No drain on that. Just a plug on top. Gives you a good view of the impeller and the wear ring, too.<br /><br />I like that flushing attachmnet idea. The newer SportJets all have them.

 

[funpilot]

Re: mercury sport jet

The gasket for the ride plate is available. And I have one also that I haven't installed yet.<br /><br />Here is a link to a site that shows the adapter for running the engine on a hose. Also the lifting ring that attaches to crankshaft end on top of the flywheel is shown. It is a 3/4-16UNF nut with a ring welded to it. If I had tapered the ring, I could have mounted it without taking off the flywheel cover. Make sure if you use one you can engage about four threads. Another photo on the site shows the engine on the stand, and the hose the adapter attaches to is visible.<br /><br /> http://funpilot15.photosite.com/Mirage/lift_ring_and_hose_adapter.html <br /><br />Take care,