1996 seadoo xp bad compression

[Jakem1]

I have 1996 seadoo xp and when I pulled the top piece of the engine where the pistons are there is a liquid and it seems to be water.
What does this mean and what do I do????????

 

[mikidymac]

That is water and is what cools the engine.
Why did you pull the head?

Your cylinder drain hoses on the side of the cylinders are plugged and not letting the water drain when the ski is out of the water.

 

[Jakem1]

That is water and is what cools the engine.
Why did you pull the head?

Your cylinder drain hoses on the side of the cylinders are plugged and not letting the water drain when the ski is out of the water.

There was low compression so I pulled it off to look at the pistons.
Now how would I go about cleaning the cylinder drain hoses?

 

[Jakem1]

The front spark plug had 105 and the back one had 119.

 

[Jakem1]

I have a 1996 Sea-Doo XP and replaced pretty much everything on it and it has bad compression. I pulled the top off and the pistons seem to be in good shape now idk what to do.
Also someone mentioned to clean the cylinder drain hose.

 

[mikidymac]

Are you sure your compression gauge is accurate?

 

[Jakem1]

Are you sure your compression gauge is accurate?

Yes

 

[Jakem1]

Are you sure your compression gauge is accurate?

i’m kind of on the verge of selling it because I’ve replaced pretty much everything and the pistons seem to be good and still doesn’t work right.
I just don’t want to sell it knowing that it’s an easy fix.

 

[mikidymac]

If the compression numbers are in fact 105 and 119 then that is your issue. It is never going to run with that low of compression. 120 psi is the minimum.
Your top end is done. At minimum you will have to have the cylinders bored oversized by a good 2-stroke machine shop and have new, larger pistons fitted.

 

[Jakem1]

The pistons look about a year old. I tried to remove the cylinders to look in there but I can’t get them to come off.

 

[mikidymac]

Pistons can "look fine" from the top but your low compression tells the true story.

 

[Jakem1]

Pistons can "look fine" from the top but your low compression tells the true story.

Makes sense, I’ve literally tried everything to get the engine apart but it’s like superglued together.

 

[mikidymac]

It doesn't look that corroded. Remove the 4 cylinder bolts in each cylinder and the exhaust manifold. Rocking back and forth the cylinders should come off.

 

[Jakem1]

I took of those bolts and more and still won’t come off.

 

[mikidymac]

You need to get the big white pipe off first then the cylinders.

Use a dead blow hammer or rubber mallet to break the gaskets free.

BE VERY CAREFUL you don't crack the cylinder water jackets by hitting too hard on the sides!

 

[Jakem1]

 

[Jakem1]

You need to get the big white pipe off first then the cylinders.

Use a dead blow hammer or rubber mallet to break the gaskets free.

BE VERY CAREFUL you don't crack the cylinder water jackets by hitting too hard on the sides!

Does anything look wrong or messed up with the pistons or cylinders, I’m not really sure what to look for

 

[mikidymac]

You still didn't remove the exhaust manifold.....

You can post pictures of the sides of the pistons but you are still going to have to have a machine shop measure the cylinders and pistons to see if they are in spec.

 

[Jakem1]

You still didn't remove the exhaust manifold.....

You can post pictures of the sides of the pistons but you are still going to have to have a machine shop measure the cylinders and pistons to see if they are in spec.

There was a gasket that seems to be non existent, is that the problem

 

[mikidymac]

No, that gasket just got damaged with removal.

I circled the cylinder water drains that were keeping water in your water jackets.
Make sure they are free and clean and the hose that goes all the way back out the ski. They can fill with sand.


As dark as your cylinders and pistons look, they really just seem to be worn out. The machine shop can verify it.

 

[orbit398]

On ur compression gauge, the only one to use is a Snapon for best results. Otherwise u will not get true compression. I just went thru this. I have two gauges that i have used for years. Engine on my 95 XP was hard to start and reading low ~120psi. So thought it was time to freshen motor. Took to local shop as they have Snapon guage. Well, compression was at 140psi. Only had carb issues
Turns out my two gauges have little adapters for use in multiple spark plug holes. That little extra volume lowers the psi reading. U need a guage with the shader valve at the end otherwise ur cylinder volume is increased by the adapter. See pics. Was a learning experience for me and hard to believe that little extra volume lowered the psi that much

 

[mikidymac]

On ur compression gauge, the only one to use is a Snapon for best results. Otherwise u will not get true compression. I just went thru this. I have two gauges that i have used for years. Engine on my 95 XP was hard to start and reading low ~120psi. So thought it was time to freshen motor. Took to local shop as they have Snapon guage. Well, compression was at 140psi. Only had carb issues
Turns out my two gauges have little adapters for use in multiple spark plug holes. That little extra volume lowers the psi reading. U need a guage with the shader valve at the end otherwise ur cylinder volume is increased by the adapter. See pics. Was a learning experience for me and hard to believe that little extra volume lowered the psi that much

Correct, those adapters will lower compression but it doesn’t have to be SnapOn. I have a few from Autozone that are perfectly accurate too. But if you have the money to spend you can’t go wrong with high quality.