96 GSX quit running, won't start

[Doctor_Venkman]

I was riding my 1996 GSX on Labor Day weekend. At one point there was a lack of power. I would give it throttle, the engine would rev but no power. Since we had just received 2 days of rain from the remnants of hurricane Harvey, the lake was several feet higher than full pool with a lot of debris. I figured that something was blocking the impeller. I shut it down and my brother towed my to a nearby dock. I checked the intake and felt nothing there. After waiting several minutes I started it up and it seemed to be good. Ran it for a quarter mile or so and it quit. Shut off just like I pulled the key. It won't restart. It cranks but doesn't seem to be firing. I put in new plugs (BR8ES 5422 thanks to the forum) but no joy. Disconnected the fuel line at the Y just before the engine and it had fuel in it.

I'm not a mechanic and I plan on taking it to see one tomorrow. Eventually I want to start doing this kind of thing on my own. That's why I'm posting this situation.

 

[Cliff787]

Welcome to the Boards!

Good knowledgeable people here for sure!

I have the exact make/model as You do since Aug. 1996 and just recently completed a full engine rebuild along with other items that needed attention.

So can I ask you if the ski has grey Tempo fuel lines on it? It'll say "Tempo" "USCG approved B-1" on the lines. If so, immediately replace those fuel lines as they internally break down and clog the carb microfilters and restrict fuel flow to the engine and will cause a lean seizure and engine damage.

Next question...when have the carbs last been rebuilt?
If recently. Were genuine Mikuni parts along with new Mikuni needle/seats installed?

How about the fuel selector and water/fuel separator? Have they also been replaced?

Is this ski new to You and don't know the history or have you owned it since new and do know where it's been?

A lot of questions. But important to know some of this info.

The sudden "shutting off" could signify that a Ground connection isn't good or that the coil is failing/has failed etc.

Let Us know what the Shop says about your ski after taking it there.

 

[Doctor_Venkman]

Thank you Cliff.

A lot of valid questions. Several of them I should have answered before submitting the post.

I bought the ski earlier this summer. I do not know the history or if the carburetor has been rebuilt as well as the fuel selector or separator

The fuel lines were replaced at some point. They are the black automotive lines and not the dreaded grey garbage.

I should also mention that it is hard to see the sparks from the plugs when outdoors. I'm not sure if they should be be stronger or not.

 

[soccerdad]

So welcome to the forum!
Nice ski (I have one as well...)
So these things need 3 basic things. Fuel, Spark and compression. Compression is the most easy to test. It should be 130 - 150 PSI and they should be close together. If one is really low, you lost a cylinder and will have to rebuild. You can usually borrow a compression gauge from a local autoparts store. I am leaning towards something in the fuel system. What do the plugs look like? Are they dry, wet, white, black, brown, or silver? You can pour a little (soda bottle cap full) of fuel mixed with a little oil down each plug hole, put in the plugs and see if tries to start. If it does, then I would start with a carb clean and rebuild. Electrical is a little more tricky just because of the number of wires around. But it does crank right? So start by opening the rear electrical box and checking to make sure all the terminals in there are nice and clean. And that the plugs in the front of the motor and the rear box are nice and clean. Start there, report back and we can guide from there.

 

[Doctor_Venkman]

Thank you for the welcome, soccerdad.

The old plugs were pretty black. I replaced them with new ones. After trying to start it several times the new ones come out and BIT dirty and slightly wet with fuel.

I'll look at investing in a compression gauge. It seems like I'm going to need one at the rate this thing is racking up shop time and labor.

 

[Doctor_Venkman]

Well, the early diagnosis is in. Possibly a stuck solenoid. After bypassing that, there is no compression in one cylinder, other cylinder is optimal. They also heard a rattling that they thought would be the crank possibly nearing it's end. That's where they stopped since further repair would be expensive.

I don't know what to do from here. Replacing the engine would cost around 2k with labor. I would rather put that toward a new or used Spark. I'm considering replacing the engine on my own and (hopefully) using whatever money I've saved into making other modifications to it.

The thing is, I've never worked on something like this. The most I've done is replace filters, plugs and such. I would definitely be jumping into water over my head. If I replace the engine myself, I'll definitely be asking a lot of questions. Starting with, what size engine can I put in it? If I'm going to do this, I want it to go fast. When it was running, it would top out at 50mph. I'd like to increase that within reasonable budgetary limits.

 

[soccerdad]

The main killer of the skis is a clogged up fuel system/carbs. Sounds like that was your issue and it killed the motor. Sorry. You can get a fully rebuilt motor for $1200 with a 2 year no fault warranty. Just drop it in and run. But you will also still need to do the fuel system stuff (lines and carbs). None of this is really too hard. If you have to pay someone, then an older ski like this probably is not the best choice. As far as motors go, the 787 you have is the only thing that will bolt back in. Otherwise you have to make new mounts, etc. And that would be a waste of time. A good running 787 in your GSX should hit around 54 MPH which is pretty fast IMHO for that hull unless you are racing it. If you want a 65 MPH ski, you have to go to a big 4 stroke (non-Spark) ski. And they are pricey. As they say, "speed costs, how fast do you want to go?"

If you want to attack the motor replacement and carbs, etc, there are plenty of resources here to help you through it. If you want a jump on and ride ski that you don't have to work on, then get a spark. But I would ride one first so you can see the difference in weight, acceleration and handling.

 

[Doctor_Venkman]

$1,200 plus a few other mods still might be more than I want to spend on a 21 year old ski. The fuel lines are the black automotive lines and not the gray junk. So hopefully they would only need to be blown out.

Speaking of other mods, are there aftermarket parts available for that model like a new hood and cowling, new covering for the handle bars, and such? I'd slso love to have a modern instrument cluster in it (ideally a GPS unit). The one now doesn't even show speed... When I can see it through the condensation.

 

[Doctor_Venkman]

I'm torn on what to do with this boat. I'm not a fan of the 2 stroke engine. Especially trying to manipulate the starter button, choke and throttle, not to mention worrying about oil/fuel mixture.