1996 GTX Bogs Down

[gtxnoclue]

I have a 1996 GTX (787 Engine).

My SeaDoo used to run fine until 3-4 years ago when the SeaDoo sank & the engine compartment flooded with water. Long story short is that the shop I used to take it to - “Fixed” a slow leak by replacing the water regulator valve (and charging me several hundred dollars in the process). The result was that the exhaust hose melted while I was in the middle of the lake leaving a 2.5 inch hole that water flowed into. They stated that the water regulator they installed was faulty which caused the exhaust hose to melt. I got the water out of the engine, sprayed WD40 on everything I could, and took it back to the shop for them to get it back in running condition.

Ever since (over the last 2-3 years), I’ve had problems with the engine bogging down at ~3200 rpm. I cleaned the RAVE valves, had the carbeurators cleaned & reassembled (by a different shop), and cleaned all the connections in the electrical box near the battery.

It seemed to run better with no bogging down. After several 30 minute trips, the engine started surging between 5,500 & 6,200 rpm. Took it to the shop & they said one of the carbeurator filters was clogged again (which they cleaned again).

Next trip out – when initially starting, it again bogged down at ~3,200 rpm. After warming up the bogging went away & it seemed to run fine for 30 minutes. There was no evidence of surging. Turned the engine off without removing the key and it wouldn’t start (wouldn’t even turn over). Waited for a short time (~10 minutes) then it turned over but wouldn’t start. When putting the key on it would beep 4 times. A side note – it seemed like there wasn’t as much cranking power when I tried to start it. At that point the battery seemed too weak to crank it

Additional note - Over the last 2-3 years (I think it coincides with the “sinking”), the buzzer does not beep loudly (at least on a consistent basis). Most times you can hear it – but barely. Occasionally it will beep loudly. After a short period (~5 or 6 start/stops) it usually goes back to being faint. Not sure if this has anything to do but thought I’d mention it.

Any ideas would be greatly appreciated. Thanks!

 

[LegalizeIt]

Take the head off and inspect the cylinder bore and piston.
If you take the rave valves off, you can see the piston skirt through the port...

It's possible the pistons had a minor seizure due to improper mixture while tuning...

Probably not, but doesn't hurt to check.

 

[roneagan@cfl.rr.com]

Have you changed the gray fuel lines?? If you have not done that it may be the source of your problems.. Do a search on gray fule lines, it will give you a lot of good information...

 

[gtxnoclue]

No I haven't done this yet. I'll give it a try. Thanks!

 

[seadoobutch787]

Those grey tempo fuel lines are the devil, they break down and create this guuey blueish crudge that will plug up your micro filters in your carbs and also your fuel selector switch.

 

[jharold]

Recitifier

Not sure if you still have the problem but I experienced the same issue. Have you tested your rectifier, remove the 15amp fuse in the white electrical box (it is plugged into the MPEM under a black cover and run the ski up. IF it it runs finr you need to replace your rectifier.

 

[timmyboy76]

Not sure if you still have the problem but I experienced the same issue. Have you tested your rectifier, remove the 15amp fuse in the white electrical box (it is plugged into the MPEM under a black cover and run the ski up. IF it it runs finr you need to replace your rectifier.

Also test rectifer by, reving up to 5500rpm, then volt the battery. In 15-ish volts, or 12-ish volts, rectifier aint no good.

 

[IDoSeaDoo]

It def. sounds like you were overheating it. The fact that it wouldn't restart after you shut it off means that the pistons were so hot, the expanded to much in the sleeve and seized. Later, they cooled off, but your startr/batt were still having a hard time cranking the engine with the larger-than-normal overheated pistons. I believe the 4 beeps means that your engine computer knows it's overheating. It does sound like a lean condition. I had a condition where my engine would get too hot, and it was due to a sticking needle/seat. They're about $20 a piece from SBT, not hard to install if you can pull off the carbs. You'll need two if you have the 787 motor.

The engine shouldn't be so hot that it scalds your hand after you've ran it good and hard.