2001 GTX 951 DI - Another winter project!

[garrettb]

I just picked up this rig tonight. I'll be selling the trailer and using something else for the time being. I just finished a 2000 GTX with carburetors, and when I saw the same ski in red, and with direct injection, I had to bite! It has 510 hours with the potentially original engine. It has 120 psi on the mag, and 135 on the PTO, so I am betting a top end at the least.

For those that do gelcoat, does this spot look like an easy spot to repair? The whole hull will need buffing, as it is faded, but I'd like to take care of that gouge. Is the swim entry step factory on this model? It looks a little sketchy, but it seems OEM enough...

It's got great spark, and a potentially good fuel pump, but won't start on it's own. The gauge flashes "maint" but I haven't looked into anything yet. Hopefully I have just as much fun working on this as my other GTX. Any DI tips for someone who hasn't touched one before?

 

[jeepfreek]

I purchased this exact model earlier in the summer. Lots of fun but the DI kind of scares me. From what I hear the fuel pressure is key on these and they have to be very close to spec in order to run at all. Mine is running with 120/125 psi compression. So I'm guessing a fuel issue for your no start. My maintenance light flashes for a minute when I startup but goes away. Maybe over the winter I'll pick up one of those CanDoo scanners and find out whats going on for sure. I'm guessing I will have to do an upper kit on mine for the compression. However it's been running like a champ so I don't want to mess with it if I don't have to. Mine has the swim step as well but it has the factory foam around it. I've put about 20 hours on it this year with (knock on wood) no issues. I did have a problem one day that it started- ran fine- 30 seconds- went into limp mode. Turned out the battery cable had worked loose. Tightened it and back to having fun. Very stable and fun ride.

 

[Mickirig1]

It is a factory boarding step. The rubber is gone. You can buy replacement rubber or use pipe insulation.
Nice looking ski too.

 

[garrettb]

I purchased this exact model earlier in the summer. Lots of fun but the DI kind of scares me. From what I hear the fuel pressure is key on these and they have to be very close to spec in order to run at all. Mine is running with 120/125 psi compression. So I'm guessing a fuel issue for your no start. My maintenance light flashes for a minute when I startup but goes away. Maybe over the winter I'll pick up one of those CanDoo scanners and find out whats going on for sure. I'm guessing I will have to do an upper kit on mine for the compression. However it's been running like a champ so I don't want to mess with it if I don't have to. Mine has the swim step as well but it has the factory foam around it. I've put about 20 hours on it this year with (knock on wood) no issues. I did have a problem one day that it started- ran fine- 30 seconds- went into limp mode. Turned out the battery cable had worked loose. Tightened it and back to having fun. Very stable and fun ride.

Funny you mention fuel pressure. I was just thinking I should start by testing the fuel pump to figure out what I really have going on. Previous owner said it will start if a little gas is squirted into the plug holes, but won't fire on its own. I am looking to either make/buy a gauge to fit in line so I can monitor fuel pressure. Has anyone done this? I have done some searching, but haven't found anything conclusive. I am looking for something reliable, but cost effective.

 

[mikidymac]

At 510 hours you better plan on doing the crank too.

 

[garrettb]

For sure. Pulling the engine is in my future. To test the fuel pump, can I just buy an automotive tester like the one shown below? I don't know what kind of fittings to look for. The seadoo test gauge (529035709) is very pricey!

 

[mikidymac]

You will also want to buy the CandooPro if you are going to get into this ski.

 

[garrettb]

I am looking into CanDoo. I just want to try some "simple" things before I spend that kind of cash. I wish it was like the VagCom software for my Audi. It doesn't need a VIN, so I can use it on as many vehicles as I want for one rate.

Now, for the interesting info. Someone has been inside this engine before. Removing the RAVE valves gave me an idea of what I am working with. I have two WSM pistons, 0.5mm oversized. They look to be in good shape, but they're big!

Judging by the looks of the valve, how many hours ago would you guess it has been rebuilt?

I also checked the air pressure regulator. Within a few cranks of the starter, the air compressor was putting out 120+PSI and would have done more had I continued cranking. The relief valve on the rail releases excess air at 80 PSI. I removed the fuel line from the rail, and when I inserted the key, fuel sprayed everywhere, so I know I have some pressure. At this point I am thinking clogged fuel injectors. I took them apart, and couldn't see any holes on the bottom side (I know they're small, but I have decent eyes!). Thoughts? I realize I need to test my fuel pump for real, but I am still figuring out a gauge.

 

[Mickirig1]

How does the official tester hookup? Does it have a port with a shrader valve? A bolt in the end of rail that comes out and you screw in a port? An automotive pressure tester is pretty cheap. They have screw on adapters with them. Or a little Mickrig you can make it work.

 

[Mickirig1]

Injection pumps also need the correct voltage. So make sure all connections are clean and protected with Dielectric grease. Fuses that feed power are clean and protected. Battery charged and at correct static voltage.

 

[garrettb]

The OEM seadoo gauge is expensive and connects either before or after the filter with a T fitting as to not "dead head" the system and allow for fuel to flow. I was going to rent a gauge from an auto parts store, but their testers only read up to 100 psi, and from what I understand, I need something that will read at least 107. I have found a few cheap kits on eBay. I'll probably pick up one of those and rig it up in some way.

After doing more browsing through the shop manual, I realized that I have fuel injectors and direct injectors. I thought it was one unit, oops! I'll take some resistance measurements on each of the four and see if that proves fruitful. Between the functionality of the injectors and the fuel pump, I am running out of things to test, so fingers crossed it is one of those two as my culprit!

 

[garrettb]

Good call on the battery and electrical, but I just took it off of the trickle charger and it works just fine. No issues there!

 

[96spxpos]

From what I can recall on other posts, DI's should be hanging around 120-125, no?

 

[garrettb]

Looks like 107 is the max I should have to read. There are three tests I can run to determine if the fuel pump is bad. One with the key in the ignition, one while starting/running, and one if I change the system to a "closed loop" and bypass the fuel rail and go straight back into the relief hose with my T gauge. I just bought a tester last night that goes to 140 PSI, hopefully it's here soon!

 

[Mickirig1]

Determined back yard mechanics will win! The info you seek, is in a book or online somewhere. FIND IT ! Then we proceed to test and repair. Buddies on a Forum are a great help too! Take it to a Pro, my Wife says. They are even stumped! Yep! I did the same thing they would do to check out or repair the problem! With no labor or parts cost!

 

[glsmohio]

I am looking into CanDoo. I just want to try some "simple" things before I spend that kind of cash. I wish it was like the VagCom software for my Audi. It doesn't need a VIN, so I can use it on as many vehicles as I want for one rate.

Now, for the interesting info. Someone has been inside this engine before. Removing the RAVE valves gave me an idea of what I am working with. I have two WSM pistons, 0.5mm oversized. They look to be in good shape, but they're big!

Judging by the looks of the valve, how many hours ago would you guess it has been rebuilt?

I also checked the air pressure regulator. Within a few cranks of the starter, the air compressor was putting out 120+PSI and would have done more had I continued cranking. The relief valve on the rail releases excess air at 80 PSI. I removed the fuel line from the rail, and when I inserted the key, fuel sprayed everywhere, so I know I have some pressure. At this point I am thinking clogged fuel injectors. I took them apart, and couldn't see any holes on the bottom side (I know they're small, but I have decent eyes!). Thoughts? I realize I need to test my fuel pump for real, but I am still figuring out a gauge.

View attachment 37466View attachment 37467View attachment 37468

you cant tell how long since its been rebuild buy looking at them. you should be cleaning them every 15 to 20 hrs.

 

[mikidymac]

you cant tell how long since its been rebuild buy looking at them. you should be cleaning them every 15 to 20 hrs.

I would not clean them every 15-20 hours if you are running the correct API-TC full synthetic oil. That is a very short interval. If you run quite a bit I would say check them every other season and go from there. Honestly mine do not get super dirty and I always run Seadoo XPS.