Quarantine Project

[medski2020]

Hi everyone! I want to introduce myself and start a project thread as I begin my watercraft restoration journey. I also have a few questions because of the very poor condition I obtained my 2000 Sea-Doo XP Limited in two summers ago.

I moved in with my wife shortly before marrying her about 2 years ago and found 2 jet skis in her brother's garage. He said they had been sitting inoperable for the last 4 years after he had a friend "rebuild" the carburetors and "tune" them to run on 93 octane. He said the Yamaha ran for about an hour before it broke down and the Sea-Doo ran for 30 minutes before breaking down. He told me if I could get them running, I could keep them.

I first washed them, filled them up with 93 octane gas, got new batteries, changed the spark plugs, took off the intakes and sprayed the carbs with carb cleaner and fogging oil. I got new batteries and managed to get the hose connected to them and fire the engines up. I was extremely excited, as I had them both running right before the summer season in 2019! The Yamaha XL700 ran very well with a bit of carb adjusting. After the tank went empty, I refilled it with 87 octane and readjusted the carb. It is a blast to ride!

However, I didn't have as much luck with the Sea-Doo. It would fire right up and rev fine out of water, but the speedometer and fuel gauge don't work. In the lake, it was taking on water and would not go faster than about 5-10 mph regardless of carb adjustment. I found that the rave valve solenoid was broken and quickly replaced it. I also replaced the missing front bumper piece.

I threw it back into the water and with some carb adjustment, I was able to get it to about 30-40 mph for about 10 minutes. It was almost as fast as the Yamaha, but it still took on water and wouldn't go faster than 5-10 mph after that brief stint of speed. I took off the exhaust pipe to look for cracks but didn't find any. I then dumped the 93 octane and filled it with 87 and readjusted the carb and it ran great for about 10 minutes before going back to only going 5-10mph and still took on water. I threw in the towel for the summer and only took out the Yamaha for the rest of the season. Last year, I only took the Yamaha out and did not touch the Sea-Doo.

Now that we're all quarantined, I decided to buy a genuine MK-BN46I carburetor rebuild kit along with new needle valve seats, gaskets, fuel lines, and fuel and oil filters. I am going to rebuild the carbs, fuel system, and oil system before we hit this summer season. Before tearing apart the Sea-Doo, I started it up and let it run with the hose in for 15-20 minutes to look for leaks, but could not find anything significant from any compartment inside. I took a video and found that there was a leak from underneath while it was running. I then turned it off, disconnected the battery and filled the hull to the same amount of water it took on in the lake previously, but could not find any significant leaks from the hull to rule out any holes or worn gaskets/o-rings. When I drained it, I found a loose hose back by the battery and started the disassembly of the exhaust and carbs. I also found two random parts in the back by the prop shaft, but don't know what they're for.

Here are the two videos of it running and with the hull filled with water:

Running with leak underneath (sorry for the gif, can't post links yet):

Same spot where there was a leak at the end of previous video, but with the battery disconnected and hull filled with water (sorry for the gif, can't post links yet):

Water drained, found loose hose but don't know where it goes:

Random part 1

Random part 2

I did not reconnect the battery after filling the hull and immediately started disassembly of the exhaust and carbs after draining the water. Before I proceed with the carb, fuel system, and oil system rebuild, I was hoping the Sea-Doo community could share their collective wisdom in helping me restore this beautiful ski properly. I would appreciate any advice you guys have regarding any aspect of this project.

I plan to keep this thread updated often with pictures and hope to finally get this Sea-Doo out on the water like it deserves.

The current issues are:
Runs only at 5-10mph
Speedometer not working
Fuel gauge not working
Loose hose in rear compartment
Leak from bottom when running with hose attached
Random parts found, don't know where they go
Carbs, fuel, and oil systems disassembled for rebuild
Stiff throttle cable that sometimes doesn't return to neutral position
Tear in seat

I really appreciate any help you all can offer!

 

[DanSquires]

1. hose is for an older style battery that requires vent, a non issue
spare part 1, you've probably got a missing bushing on the exhaust pipe.. there's two of them, one on the front of the engine and one on the backside of the cylinders.
spare part 2, part of an old battery
if running at 5-10 mph, but at full rpm, you need a wear ring/impeller rework, you may be experiencing cavitation through the carbon seal as well if water is leaking from there
speedo not working, probably the paddle wheel
fuel gauge not working, probably the baffle needing the F1 fuse repair. Since you're rebuilding the fuel system, do the repair
throttle cable, may be carbs all nasty and gummed, may need some cable lube.
seat, jet trim makes the nicest seat covers on the market, in my opinion

 

[mikidymac]

And just to follow up, follow the carb rebuild sticky at the top of the 2-stroke PWC section.

Never ever run the ski out of the water for more than a couple minutes even on the hose because you will burn up the driveshaft seal. You probably already burned up the driveshaft seal running it for 20 minutes out of the water.

 

[medski2020]

Thanks for the info, DanSquires. Also, mikidymac, thank you for the advice. I will not keep a ski running out of the water more than a few minutes from now on. I have reviewed the carb rebuild walkthrough and have been doing some reading on the fuel and oil systems, including the F1 fuse. Looks like this thing needs a lot of work to get to the water in decent shape.

I checked the carbon seal and it has about 1/4 inch of play when I pull on it. I suspect this was the culprit for the ski taking on water.

I also removed the jet pump to inspect the impeller and wear ring since they're coming off for the carbon seal replacement. This is what I found:

I'm beginning to think my brother in law may have taken this ski in shallow waters.

I'm planning to order a solas 15/20 impeller, wear ring, and a carbon seal replacement kit. Is the impeller an appropriate size for a ski I plan to keep stock? The jet pump drive assembly appears to be in good shape.

 

[mikidymac]

Just send that one to Impros or Skat-Trak and get it refurbished. You really can’t do much better than the OEM impeller.

 

[medski2020]

I got the new carbon seal kit in today and removed the old seal with a significant difference in length between the two. I guess this explains why there was so much play without any effort along with why the Sea-Doo is taking on water.

 

[medski2020]

I started removing the old impeller and found that the nose cone has a crack that reaches the inside of the cone. Is the correct part number for a new nose cone 295500542?

Below is a picture and a gif of the shaft/bearing play. The shaft moves in and out about 1/8 of an inch without any vertical or horizontal movement. Is it safe to say the bearings are okay for continued use?

Nose cone crack:

Shaft/Bearing play

Edit:
Got the old impeller off and found that the fins on the jet pump assembly housing were broken off, most likely by an undisclosed rock. Looks like I'll be sourcing one in good condition along with a nose cone. Here's what it looks like: