1997 XP 787 No Start / gash in hull

[GrupaNation]

I got my first SeaDoo on Wednesday this week, and (against my better judgement) I bought it private for cheap. It started strong, ran well and sounded alright when I bought it. Thursday, I did some basic maintenance while it was on the trailer. I greased the mid bearing in the rear, put 2 new spark plugs in (NGK from a SeaDoo dealership), put dielectric grease in the spark plug caps, installed a fully charged new battery, and threw a glug of 2-stroke oil in the gas tank just in case the oil injection doesnt work. I hit start and it fired right up, a little white smoke came out but nothing concerning. I let it run for 20 seconds, shut it off, filled the tank with gas and headed to the lake. Once it was in the water, it turned over but wouldnt start. I tried for 15 minutes to start it, holding the start button for 5-10 seconds with 1 minute break in between, but no success. Defeated and pissed, I drove it home and put it in the shed. I took the spark plugs out and they looked wet like it was getting gas (I shouldve took a picture). I grounded them to the block and they sparked when the motor turned over. But now it wont start out of the water either. Can anybody help me figure out why this wont run? My next diagnostic is to check compression.

The second thing is it has a patch on the bottom that I need to redo. What tools do I need for this? Can someone recommend a good fiberglass repair kit and gelcoat repair kit? Or a good guide to follow?

 

[kenfyoozed]

Start by downloading a manual for your model. They are very helpful. I agree I would start with compression. If that checks out, and it getting spark, maybe squirt a bit of premix down the plug holes and see if it will fire off. I would also double check all the fuses, both front and rear. Also does the beeper work? Are you getting the two beeps?

 

[GrupaNation]

Start by downloading a manual for your model. They are very helpful. I agree I would start with compression. If that checks out, and it getting spark, maybe squirt a bit of premix down the plug holes and see if it will fire off. I would also double check all the fuses, both front and rear. Also does the beeper work? Are you getting the two beeps?

I did download the manual and looked it over as best I could which is why I did those couple basic maintenance items. It beeped when I bought it but now that I think of it, I didnt get the beeps thursday when i started it. so what could that mean?
Is it possible the spark is weak too?

 

[kenfyoozed]

I would also check the battery, I know you said it was new but after all that starting it could be weak as well now. Pull it out and top off the charge. On my GTX if the battery gets low it won't beep and then I start having hard starting issues. The two beeps helps me to know all is good to go.

 

[mikidymac]

If the plugs are wet it's probably flooded. Turn the gas off and crank it over with it wide open a few times then urn the gas back on and install new plugs and see if it will fire.

Flooding is usually caused by bad needle and seats or diaphragm in the carb. Any new to you ski should have the fuel system including carbs gone through and only use Genuine Mikuni parts, not aftermarket carb kits.

Compression is the big one because that can cause no start or hard start in the water and it will flood if it can't burn the fuel. Perfect compression is 150 psi, 130 is about the minimum to run good and at 120 psi it is too low to start in the water.

For the bottom repair, it's pretty bad and someone did a 1/2 ass repair. That goes through the hull so I wouldn't put it in the water until you get it fixed. You will have to grind off the old repair and any loose glass. Clean really good with acetone over and over. If you just want to use it for the summer then get some marine-tex and just do a temporary repair. Over the winter get some fiberglass cloth and epoxy resin and fix it correctly.

 

[GrupaNation]

If the plugs are wet it's probably flooded. Turn the gas off and crank it over with it wide open a few times then urn the gas back on and install new plugs and see if it will fire.

Flooding is usually caused by bad needle and seats or diaphragm in the carb. Any new to you ski should have the fuel system including carbs gone through and only use Genuine Mikuni parts, not aftermarket carb kits.

Compression is the big one because that can cause no start or hard start in the water and it will flood if it can't burn the fuel. Perfect compression is 150 psi, 130 is about the minimum to run good and at 120 psi it is too low to start in the water.

For the bottom repair, it's pretty bad and someone did a 1/2 ass repair. That goes through the hull so I wouldn't put it in the water until you get it fixed. You will have to grind off the old repair and any loose glass. Clean really good with acetone over and over. If you just want to use it for the summer then get some marine-tex and just do a temporary repair. Over the winter get some fiberglass cloth and epoxy resin and fix it correctly.

I have a bunch of 3m 5200 Marine that I used for rivets on my aluminum boat. It dries in about 1 week. If I just want a temporary fix for now, can I clean away the old patch and use this instead of marine-tex? If it isnt a good substitute then I will just get the marinetex.

 

[mikidymac]

I wouldn't use the 5200. You want something more solid for the bottom of the hull like Marine-Tex.

 

[GrupaNation]

How much should I get if you had to give a rough estimate?

 

[mikidymac]

I think the 14oz can kit would be enough.

 

[GGuillot]

The second thing is it has a patch on the bottom that I need to redo. What tools do I need for this? Can someone recommend a good fiberglass repair kit and gelcoat repair kit? Or a good guide to follow?

Dang, am I looking down the keel? It's just years of wear and tear on the bottom, not necessarily damage. I had similar wear on both of my skis when I got them, more so on the GSX. I'd strip it, flip it and die grind out some of the deeper gouged areas and fill with marine tex, then sand/prep everything for gelcoat. Then I'd get a quart of gelcoat and cover it to protect the area.

I did this and taped off a section on my GSX, it wasn't as bad as yours but it needed attention, bare fiberglass exposed isn't good.

Marine Tex is on Amazon and I used FGCI | Fiberglass Coatings for the gelcoat. What you see on the GSX is 2 coats brushed on and costs about $45 for a quart that I used. Luckily they sell a yellow that should match easily, unlike my choices to match the indigo blue.

 

[GrupaNation]

Dang, am I looking down the keel?
FGCI | Fiberglass Coatings for the gelcoat.

yeah, thats the keel. There is definitely damage to the fiberglass because when i took it out of the water Thursday water came out of the drain plugs. Theres got to be a hole underneath somewhere so I think I have my hands full on this patch job.
Is this the gelcoat youre talking about? If so, I'll keep that saved so I can get it when I'm ready.

 

[GGuillot]

yeah, thats the keel. There is definitely damage to the fiberglass because when i took it out of the water Thursday water came out of the drain plugs. Theres got to be a hole underneath somewhere so I think I have my hands full on this patch job.
Is this the gelcoat youre talking about? If so, I'll keep that saved so I can get it when I'm ready.

Get this one...Canary Yellow Brushable Exterior Gelcoat Quart Kit w/1 oz. MEKP - 137495

For a few more dollars it includes the MEKP you'll need to mix in. Do it in 2 applications, pint at a time. You've only got about 10 minutes to get it applied before it gels on you. Wait about 30-40 min to apply the second coat, next day start the sanding/smoothing then polish etc.

Check the threads out in my signature block when I did it, just make sure the mixture ratio is dead on and follow the ambient temp guidelines. You don't want it too hot or cold, about 75 degrees is ideal. Buy disposable pans and brushes. I used the cheap little plastic pan from Home Depot that works with 4" rollers.

After you do the filling and repair with the Marine Tex, just tape off the area you're doing and prep with 150 grit, then clean with acetone and apply after you've mixed it.

 

[GrupaNation]

Thank you everybody for your help. Hopefully I can do some tuning on the engine this week and figure out what's wrong. I will post updates if I make any breakthroughs and show how the hull repair goes.

 

[GrupaNation]

Not sure if anybody is following this thread anymore, but i worked on the ski last night. I charged the battery for a couple hours and tried to start it again, I still dont get beeps when attaching the DESS, but it turns over strong. The compression read 130/135psi in both cylinders, I took the intake/flame arrestor out and sprayed some carb cleaner in the carbs.

If the plugs are wet it's probably flooded. Turn the gas off and crank it over with it wide open a few times then urn the gas back on and install new plugs and see if it will fire.

I did what mikidymac said, purged the fuel lines and dried off the plugs and turned the gas back on, but still no start. I'm guessing the next step will be to replace all the fuel lines and clean the carbs.

Attached is a pic of a wire that seems fried. Its on the exhaust side under the hood. Do I need to fix it?
The other pic is the fuse box. I dont have a cover for it and I feel like I need one.

 

[kenfyoozed]

Starting fluid is not a good idea on these engines as it flushes away the oil that is used to lube the engine. And you confirmed you are getting a strong spark? then maybe start checking those fuses and that possibly that wire has something to do with it. What does it attach to on both ends?

 

[GrupaNation]

Starting fluid is not a good idea on these engines as it flushes away the oil that is used to lube the engine. And you confirmed you are getting a strong spark? then maybe start checking those fuses and that possibly that wire has something to do with it. What does it attach to on both ends?

I took the spark plugs out, ground them to the engine and they both sparked when the engine turned over. I dont know how to check the "strength" of the spark but they definitely were firing. As for the fuses, I checked all of them and they are all good. The wire is plugged into the block as shown in this other pic.

 

[GGuillot]

Not sure if anybody is following this thread anymore, but i worked on the ski last night. I charged the battery for a couple hours and tried to start it again, I still dont get beeps when attaching the DESS, but it turns over strong. The compression read 130/135psi in both cylinders, I took the intake/flame arrestor out and sprayed some carb cleaner in the carbs.



I did what mikidymac said, purged the fuel lines and dried off the plugs and turned the gas back on, but still no start. I'm guessing the next step will be to replace all the fuel lines and clean the carbs.

Attached is a pic of a wire that seems fried. Its on the exhaust side under the hood. Do I need to fix it?
The other pic is the fuse box. I dont have a cover for it and I feel like I need one.

Sometimes, depending how rough the ski is, a complete strip it down and rebuild may be in order. On my 2 skis this is what I did. You've got hull wear and damage underneath to address anyways.

What you get accomplished with the strip and build up approch. 1. You get a good look at everything and it's a way to verify what's still good or not. 2. Everything gets cleaned. 3. You learn everything about the ski quickly. 4. It won't surprise you with an issue later out on the water.

Some things you can get done that you may discover. Starter needs rebuilding ($20). Cooling lines, fittings, paths may be plugged. Fuel sender needs repair. Risidue in fuel tank. Vent fittings, there's 2, gummed up. Jet pump needs rebuildiing, new wear ring, etc. Welch plug on exhaust needs repair. Electrical connections/plugs need cleaning. Engine may need a refresh, new seals, etc. Check or inspect the crank seals and bearings. Ck balance shaft seals and bearings. Clip spark plug wires. Rebuild cabs with oem kits, new needle/seats verify springs and pop off. Inspect carbon ring, regrease pto flywheel. Inspect and adjust oil pump and throttle cable. Replace all lines.

It's had 20 yrs of use, a complete overhaul is not out of line. You do this and you set your self up to have trouble free times ahead when getting out on the water.

My 18 yr old and I spent hours out on the water yesterday, took the GSX and GTX out to remote parts of the lake, everything performed flawless for us. But I went to absolute bare hull on both skis and spent quite a bit of $$ and time to reach a certain level of performance and reliability.

 

[mikidymac]

THe wire is the temperature sensor wire and I would fix it although with a non functioning beeper it will not be telling you anything. The sensor will not cause it to run or not. Try putting a little premix down the carbs and see if it will fire.

 

[GrupaNation]

Carbs came out today since fuel lines were being replaced. Does anybody know where i should have the high speed screw set at? I marked where they were set before I turned them with a marker. Then I started to screw them in to see if they were set the same. The PTO screw was already tight so I backed it off and just tightened it snug, but the MAG screw turned a quarter turn before it got snug.
What should I set these at for my "default" before I put then in the ski? I dont want to lean it out.

 

[JeremyD615]

The factory setting for the high speed is closed. That’s where I would start.

I know you’ve already dug into this quite a bit, and I’m surprised nobody has brought it up, but if your gauge is accurate those are borderline compression readings and may be your problem. It should start and run on the trailer with those numbers, but you’re getting awfully close to rebuild time... Considering the condition of the hull, I might think about finding another ski to work with and using this one for parts. Unless you’re up for a project, in that case let’s go ahead and resurrect this thing!

 

[GrupaNation]

The factory setting for the high speed is closed. That’s where I would start.

I know you’ve already dug into this quite a bit, and I’m surprised nobody has brought it up, but if your gauge is accurate those are borderline compression readings and may be your problem. It should start and run on the trailer with those numbers, but you’re getting awfully close to rebuild time... Considering the condition of the hull, I might think about finding another ski to work with and using this one for parts. Unless you’re up for a project, in that case let’s go ahead and resurrect this thing!

Oh baby I'm resurrecting the beast. She ran the other day so once the new fuel lines and carbs are on she should run great. Maybe in a year or two I'll do a rebuild but I think she can get through this summer. I cut open the gash in the bottom and ground away all the old patch. I filled it marine tex and layered fiberglass to build it up and I think it's coming along well! Itll get a sanding and another coat of marine tex tomorrow, then it should be ready to ride!

 

[GrupaNation]

The factory setting for the high speed is closed. That’s where I would start.

Isnt running the high speed adjuster closed running it really lean? The carb adjustment sticky says that 3 turns out is the richest. Can I meet in the middle and start at 1.5 turns out?

 

[JeremyD615]

I love seeing these things brought back to life. I’ve restored a jet boat and a 96XP that were both trashed to the point they had plants growing in them. It’s absolutely worth it, but I wish I had known how much work I was getting myself into when I started that first project!

 

[JeremyD615]

Isnt running the high speed adjuster closed running it really lean? The carb adjustment sticky says that 3 turns out is the richest. Can I meet in the middle and start at 1.5 turns out?

If it’s still got the stock airbox on it, start with the high speed screws closed. If that makes you nervous, although it shouldn’t since that’s how it came from the factory, set them to just barely cracked open. A little goes a long way with the carb adjustments... also keep in mind that the main jetting is different between the mag and pto carbs on this ski. Don’t mix them up. The mag side should have a 142.5, and the pto should be 147.5.

 

[GrupaNation]

main jetting is different between the mag and pto carbs on this ski. Don’t mix them up. The mag side should have a 142.5, and the pto should be 147.5.

The setting isn't adjustable without taking the carb out and replacing the carbs though, right? I'm still new to carbs. Can you clarify what you mean?