XP Rebuild

[Schouty]

I have been running a 99 XPL for a while till my rectifier went a few years ago and melted the MPEM and part of the harness in the process. I purchased a new MPEM and harness, but then I let the ski sit for about 5 years. In the mean time I picked up an 03 XPDI hull that was in really nice shape. I wet sanded and polished it and repaired the Gelcoat with a repair kit from Spectrum. The gel coat came out pretty well for being done by a rookie. So I have started reassembling the ski and I am stripping everything from my 99 and putting it in the 03. One reason I didn't try and clean up the hull on my 99 was that it was very faded and the deck was painted by the previous owner and the paint was starting to lift. Anyway, so far everything has been pretty straight forward except for a few of the water feed hose from the pump was bigger. But my next question is the engine always ran strong till the rectifier went and before I put it back in I am going to check compression. But I am concerned about the bearings for the balance shaft being questionable. Should I just go through the whole engine? Or is it easy enough to remove the counter balance shaft and just replace the bearings?
Thanks,
Chris

 

[Boyd12]

Chris:
Do you have any idea how many hours are on the engine?
The balance shaft is the second part you put in the crankcase after the crank shaft so it is a total rebuild. How is the oil in the balance shaft cavity?

 

[mikidymac]

As long as the engine didn’t get water in it, it should be fine. And as said above the entire engine has to come apart to do the balance shaft so no point in just doing that.

 

[Schouty]

Embarrassing as this sounds, I did not know there was oil in the crankcase for the balance shaft. I'll have to check and see. Also I was reading where you can drill the rave valves and use the engine vacuum to operate them instead of the solenoid. Is this worth doing or leave that stock?
Thanks

 

[Boyd12]

"Embarrassing as this sounds, I did not know there was oil in the crankcase for the balance shaft." Most people dont know as the SD manuals, in some cases, dont mention it. It is one of the most common causes of engine failure. Usually the engine is junk afterwards. Good luck with your boat!

 

[mikidymac]

No, don't drill the raves, use the solenoid.

 

[Schouty]

So I checked the oil and it looks really clean. Should I change it while the engine is still out?
Ok, I'll leave the rave valves alone and just check and make sure they are good.
Thanks for the help, it's really appreciated.

 

[mikidymac]

Yes, change the oil.

 

[Schouty]

So the oil is nice and clean, but I'm still going to replace it. I pulled the carbs apart and cleaned them and reassembled using genuine mikuni kits. Just have to set them and check pop off pressure. Now I'm on to the pump, I pulled it apart to replace the wear ring. I've seen a few companies selling rebuild kits for the pumps, are they any good? I've seen venom has a kit, is it worth going with them?

 

[mikidymac]

I haven't seen anything of quality form Venom. Unless it is leaking water or has damage there isn't a reason to rebuild the pumps.

 

[Schouty]

Ok, good to know. Thanks.
When I pulled the cone so I could pull there impeller I had a little bit of water come out of the cone when I loosened it. They oil wasn't milky, just stunk. Lol.

 

[mikidymac]

If that cone has a hollow spot on the outside water could have just been in there when you took it off. If there was actually water in the pump then the seal needs to be replaced.

 

[Schouty]

I'm replacing the seal regardless, it's not very soft anymore and if I have it apart I might as well change it. Plus the needle bearings inside feel a bit odd when I spin them by hand. I think you are right, because the oil showed no signs of water mixed in it. I have the brass pump, when I put the wear ring in, should I put in small screws to hold it? Or just freeze the wear ring and slide it in?
Thanks again

 

[mikidymac]

No screws on the brass pumps. Just freeze it and happer it in with a block of wood.

If you replace the bearings follow the manual exactly as you have to set their depth per the manual, you can't just push them in and guess.

 

[Schouty]

Ok, I'll check out the manual for the placement of the bearing's. Also, I just want to double check. But just use a good 30w oil for the crank case?
Also, coming through the transom there are the different tube fittings. There is one on the right side of the machine all the way at the bottom, below the steering cable. I can't find what it is for. My old ski just had it looped to one of the two fittings above the pump. The ones for the self bailers. Does anyone have any idea where it goes? I looked in the manual but don't see anything.
Thanks

 

[Schouty]

So the ski is running now, pump is rebuilt and just about all together. My next question is does anyone have pictures of how the hull vent hoses should be laid out? The 03 DI hull is different than my 99 hull was. There are two smaller hoses under the seat and two going straight down from next to the fuel fill.

Here are some pictures of the progress.

 

[Boyd12]

Wow, that looks GREAT! More pictures please! In regards to hull vent hoses, which ones? The cooling system that vents out the side or the ones under the seat???

 

[Schouty]

Thanks! Mainly just the two under the seat. I downloaded the parts manual and it just shows me two little hoses that go straight down. I'm not sure if that's right.

 

[Boyd12]

Here are a couple images from the parts manual. I hope this helps.
I have a Di with a Di engine in it. I would much prefer a set up like yours! Good luck with your project!

 

[Schouty]

Thanks, I have that part of the venting done. I am trying to see how the large vent tubes are laid out. Mainly the two under the seat. They are the ones that vent the hull out.

 

[Schouty]

So I've been running the ski and it runs great besides a few little hiccups that I was able to resolve. I think I'm not getting the mph I should be, I'm just under 60. So about the ski, it's an 03 with a carb motor in it. It has a Miller head, r&d intake, Reed stuffers, jetted carbs, chokes deleted, Solas concord. New wear ring and fresh carbs. I'm also not getting the rpm I should, 6900. With what's done to my ski, that should turn a concord. Right? If not, is there anything I could do to get some more rpm?

I have to do a compression check.

Next question, I am cavitating out of the hole. The only part that's not new is the carbon ring. Is there a way to tell if that's where I am pulling in air?

Thanks in advance.

 

[Boyd12]

Most of what you did, I did on my 2000 XP but without the impeller. Top engine speed was 7,000 and GPS 64 mph.
What is the peak RPM you are getting?
How do the plugs look?
What is the compression?
Boyd

 

[Schouty]

I'm getting 6900 rpm. I have to check the compression. I'm planning on going through the motor this winter, I want have the bottom end done, especially. Just to be safe.