Sport Jet 90

[emmalj]

I have a sport jet 90 , does anyone know how the cooling system works on this boat? I have a baja blast jet boat and I was cruised around for about 2 hours last weekend and when I pulled into the marina the boat started shuddering a little and when I tried to restart it seemed like the motor was seized. I even tried to pull with a rope...nothin. after it cooled down it loosened back up. Any help?

 

[kenimpzoom]

Re: Sport Jet 90

The jet output is used to pump cooling water. Look at the black 1 inch hose coming from the jet housing. The hose will lead to the engine. If this hose gets plugges with junk, no more cooling and engine overheats. If engine overheats, it will seize up.<br /><br />You need to check the compression on all cylinders to see if any damage was done.<br /><br />Also need to check overtemp warning horn. It should have gone off before engine got that hot.<br /><br />Ken

 

[emmalj]

Re: Sport Jet 90

Thanks, there is a buzzer that has gone off a few times but someone told me that was going off because there was some debris in my impeller housing? Does that sound right or was it indeed overheating? I appreciate the help.

 

[kenimpzoom]

Re: Sport Jet 90

The buzzer going off indicates overheating. The overheating is due to debris in the cooling system somewhere.<br /><br />Take off that hose and make sure it isnt plugged up. Its real easy to take off, just need a cresent wrench. Then you need to pull off the jet stator and look in there to check for junk. That is also real easy to take off.<br /><br />I would also suggest you get a manual for it. Iboats has them or search ebay for "sport jet".<br /><br />And check your compression.<br /><br />Ken

 

[emmalj]

Re: Sport Jet 90

Hey there I know it may sound crazy but where exactly is the stator located?

 

[emmalj]

Re: Sport Jet 90

Also do you know where all the lubrication or geal oil is supposed to be put in on the lower unit. I mix my oil and gas 50:1 is there anything else I am supposed to be doing? You have been a lot of help already, and I do have a manual on the way. Thanx

 

[kenimpzoom]

Re: Sport Jet 90

There are two "stators" on this engine/jet. The electric stator is under the flywheel on top of the engine. It generates the elctricity to make the spark plugs spark.<br /><br />The other stator is part of the jet drive. The jet pump impeller pumps water and the stator directs the water.<br /><br />The stator has oil in it that lubes the jet driveshaft.<br /><br />There is also a gearbox that has lube in it too.<br /><br />Your manual will tell you all and exactly how to check and change both of these oils. Stator oil is easy. Never done the gearbox oil so cant comment on that, but it looks pretty easy.<br /><br />Ken

 

[emmalj]

Re: Sport Jet 90

I found the 1" hose you were talking about but I have'nt removed it yet. I have fully charged my battery and I can"t get my motor to turn over. I know the starter is working because I can hear it trying to turn the motor over and it is getting hot from being under such a load. I even tried to attach a rope to the top of the flywheel and I can barely get it to turn. I am afraid something bad has happened. Any ideas?

 

[kenimpzoom]

Re: Sport Jet 90

When it was last running, was it overheated or was it OK?<br /><br />Is there any debris in the jet pump?<br /><br />Take out the spark plugs and see what they look like.<br /><br />You may have water in the cylinders. Or the engine may have totally seized up due to overheating.<br /><br />Ken

 

[SB]

Re: Sport Jet 90

I had a similar problem. It turned out that one of the magnets had fallen our of the inside of the flywheel. If you have a good battery and starter the engine should at least turn over.<br /><br />The flywheel is easy to remove but expensive to replace.