1996 GTI 718 Starting Issues

[K Huf]

I am new to the Seadoo scene but I have been boating for years. I picked up a pair of Seadoo PWC's, 1996 GTI 717 and a 1994 GTX. The GTX engine is in pieces so I am focusing on the GTI. The issues I am having are as follows.......

Initially when I connected a battery it blew the 5 AMP fuse. After a series of tests I found that it only blew if the magneto was plugged in. Figured that the stator was bad and pulled the flywheel. The stator and flywheel are very clean so I figure they may have been replaced recently. Connected the battery and the starter spins but only with the magneto plugged in. And now the 5 AMP fuse no longer blows. Re-installed the flywheel and it cranks and fires on starting fluid but after releasing the start button it is totally dead unless I unplug the magneto and plug it back in. When I re-connect the magneto plug it starts to crank without the start button being pushed. Then it will crank again. Compression is about 130 PSI on both cylinders.

Not sure where to go from here.

 

[GGuillot]

The stator and flywheel are very clean so I figure they may have been replaced recently.

Just because it's clean is not a good way to determine if it's good or not. I'd do an ohm test with a meter, per the service manual guidelines.

Re-installed the flywheel and it cranks and fires on starting fluid but after releasing the start button it is totally dead unless I unplug the magneto and plug it back in.

I wouldn't use starter fluid anymore, just not a good idea on these skis. Sounds like there's definitely an issue with the magneto, so you need to rule that issue out first. Then....go through the fuel system, if you just picked it up I'm sure the carbs need a good cleaning and a through rebuild, wouldn't hurt to replace lines and get some genuine carb kits when you do it. Might be a compounding problem, both magneto and carbs.

I wouldn't stop there, maybe get it running, but before sticking it in the water I'd go through everything, jet pump, ck the bailers, replace the oil injector lines. You don't want to fry the top end or sink it on the first water test.

Compression is about 130 PSI on both cylinders.

Not the best, but it should start and run on 130 psi, but you may need a rebuild sooner than later.

 

[etemplet]

You da man figuring all that crap out !! You got the combination. 130PSI isn't very good compression but you never know, it may come up after you run it a bit. Generally if the compression is that low you will see some physical damage. My experience anyway.

I'm not much help on the electrics butI would suspect the rectifier with that strange issue and go from there. There may be a small ground wire that connects to the mag cover. Make sure that is in place and it is clean and making good contact. Good Luck.

I think that GTX is gonna have a 657X engine in it. I'm building one of those right now. Boy O Boy I thought I had a good spare engine that just needed some love even with a few broken bolts I had my hopes up. Got to the crank and had to give it up. I had a 1995 that was great for pulling tubes and such, better than the 1996 GTI. It had some grunt !! Not fast tho. Good luck with that one.

 

[GGuillot]

I would suspect the rectifier with that strange issue and go from there.

Rectifier? How did you arrive at this assessment? He's barely got it running with starter fluid so far...

I wouldn't throw money at swapping the rectifier at this point, he has no way of testing it until he can get it running with a stable idle on the hose.

 

[K Huf]

I tested the generator coil which per the shop manual is the black/red and black wires, has 50 ohms. The charge coil, yellow/black and yellow wires, has 0.6 ohms. all within specs according to my shop manual.

Yes, replacing fuel lines, rebuilding the carburetor, are all on my list but need the figure out the electrical issue. The strange thing is the 5amp fuse blowing at first but now is not blowing. Also after cranking and firing I have to unplug and re-connect the magneto before it will crank again.

 

[GGuillot]

I tested the generator coil which per the shop manual is the black/red and black wires, has 50 ohms. The charge coil, yellow/black and yellow wires, has 0.6 ohms. all within specs according to my shop manual.

Yes, replacing fuel lines, rebuilding the carburetor, are all on my list but need the figure out the electrical issue. The strange thing is the 5amp fuse blowing at first but now is not blowing. Also after cranking and firing I have to unplug and re-connect the magneto before it will crank again.

Run down all the ground points on the ski, typically when unplugging/plugging something to reset it can be ground issue related. Typically there's a ground point in/at the MPEM (ECU), the battery, the starter and the engine, which will all tie in together.

 

[etemplet]

Sounds like your coils are good. Not being an electronics guy but what blows the fuse is when voltage tries to come through the back door. I had a rectifier issue on my SPI (1996) that fried the MPEM. Actually blew the diode along "with" the 5 amp fuse. It was easy to find as the rectifier was dead shorted internally. Something is leaking voltage. I'd check the start/stop switch but rectifiers don't cost all the much.

You could test the MPEM's indiviual wires. Then you may have to get into the connectors to the wires in question. Doesn't sound like the problem is your MPEM but you never know.

 

[K Huf]

MPEM is new. Next free time I get I will check all the ground points.

 

[etemplet]

Wow Good luck man !!! The electronics on these skis will take you to school.... I got a couple right now.

 

[K Huf]

I found a major problem tonight. There was a mouse nest up inside the dash. The wires to the multi-gauge are chewed up. Looks like the Speedo wires are O.K. Trying to figure out how to get the gauge out. I may need to replace the wiring harness.

 

[etemplet]

I guess we'l log that troubleshooting process under "expect the unexpected."

 

[K Huf]

How does that LCD multi gauge come out?

 

[etemplet]

Some of them just pull out. The gauge comes out of the rubber exterior. Gently. I'll check for you tomorrow.

 

[K Huf]

Thanks. Pulled out from the front. Wires are chewed pretty bad. Getting a used gauge and complete wire harness from eBay.

 

[etemplet]

Looks like you identified a potential problem.

 

[K Huf]

I replaced the gauge and wire harness that comes down through the front hatch. So now I don't have a short and the fuse does not blow when I connect the battery. But when I put the key on the DESS post the gauge does not come on. I poured some gas/oil mix into the carburetor and it cranked and fired up. It ran until the gas was consumed. After 2 or 3 times of cranking and firing everything was dead until I disconnected and reconnected the battery. Then it would crank and fire one time and then dead again. (When the negative cable contacts the battery I hear a click in the electrical box). Disconnected the negative battery cable and when it was reconnected the engine cranked without pushing the start button. I tested the start button with a multi-meter and it seems to be making and breaking the circuit properly. I am suspecting that the starter solenoid is malfunctioning. Am I on the right track? Also, any ideas about the gauge not coming on? And I don't get the 2 beeps when I put on the key.

 

[GGuillot]

I replaced the gauge and wire harness that comes down through the front hatch. So now I don't have a short and the fuse does not blow when I connect the battery. But when I put the key on the DESS post the gauge does not come on. I poured some gas/oil mix into the carburetor and it cranked and fired up. It ran until the gas was consumed. After 2 or 3 times of cranking and firing everything was dead until I disconnected and reconnected the battery. Then it would crank and fire one time and then dead again. (When the negative cable contacts the battery I hear a click in the electrical box). Disconnected the negative battery cable and when it was reconnected the engine cranked without pushing the start button. I tested the start button with a multi-meter and it seems to be making and breaking the circuit properly. I am suspecting that the starter solenoid is malfunctioning. Am I on the right track? Also, any ideas about the gauge not coming on? And I don't get the 2 beeps when I put on the key.

Are you looking at a wiring schematic? The info gauges need two 12 volt sources to activate. Check the purple and the red/wht going to it I believe. You need to verify if you have a good beeper or not, usually jumping 12 volts directly to it will tell you, but sometimes they can still be intermittent. You can easily test the solenoid, verify you're getting 12 volts on the yel/red to it. Remove the solenoid and jump 12 volts to it and see if the large poles are closing for the batt to starter connections.

Sounds like it's able to run, so after addressing the electrical, getting 2 beeps etc, I'd move on to going through the fuel system. These skis are finicky with the carbs, like I was saying above since you just picked it up you'll need to address this..

 

[K Huf]

Thanks. I have a shop manual and I will continue going through the electrical, then on to the fuel system.

I am now suspecting that the motor has been swapped out. It is a 717 with a single carburetor. The choke cable is not connected and has a straight rod end for a dual carb.

 

[etemplet]

I don't think your model ski came with a dual carb set up. I've had a few GTI's in the last year and none have had a dual carb set up, (1996, 1997, 2004, 2005). I had a 196 SPX that was a dual carb set up. I guess that is up to you but to save money I'd go with a single carb.

 

[K Huf]

I got the original MPEM programmed, installed it today and it fired right up. Smoked a lot and I am getting a black fluid out the exhaust.

 

[etemplet]

Yay !!!! Gotta run it a bit to get everything cleared up. Sometimes the Crank seals on the rotary valve leak a bit and all that sorta builds up in the crankcase when the engine doesn't run regularly. Take it to da Ri-ver... put it in the Wa-Ter.

 

[motoring]

Are you looking at a wiring schematic? The info gauges need two 12 volt sources to activate. Check the purple and the red/wht going to it I believe. You need to verify if you have a good beeper or not, usually jumping 12 volts directly to it will tell you, but sometimes they can still be intermittent. You can easily test the solenoid, verify you're getting 12 volts on the yel/red to it. Remove the solenoid and jump 12 volts to it and see if the large poles are closing for the batt to starter connections.

Sounds like it's able to run, so after addressing the electrical, getting 2 beeps etc, I'd move on to going through the fuel system. These skis are finicky with the carbs, like I was saying above since you just picked it up you'll need to address this..

 

[motoring]

im looking for the schematic for my 1996 gti 720 ski. i have the manual but no wiring schematic
my ski has dual carbs if that makes any difference. i have two 97 gti and they both come with single carbs i guess seadoo found the secound carb isnt worth the trouble i heard a 5 hp increase only.which is something, but

 

[mikidymac]

All 720's are rated at 85HP no change with single or dual carbs.

 

[GGuillot]

im looking for the schematic for my 1996 gti 720 ski. i have the manual but no wiring schematic
my ski has dual carbs if that makes any difference. i have two 97 gti and they both come with single carbs i guess seadoo found the secound carb isnt worth the trouble i heard a 5 hp increase only.which is something, but

Did you download the service manual? SeaDoo Manuals - FREE PDF Download! If it's not in the 1996 manual, download the 1997, should be close enough, most of the wire color coding is consistent across models.