1997 XP losing and gaining power

[pgway]

I have a '97 XP I purchased new in 1997. I have always been a maintenance nut performing everything called for in the maintenance schedule every year. This season it has been running great, as usual, until two weeks ago. When I start to ride it will run well until I hit a decent size wave. It will then not let me go over 30 mph until the next wave when full power resumes. In rough water it goes through this cycle wave after wave. In calm water I can travel for miles at full throttle and have no loss of performance.

I have checked the internal filters in the carbs, the diaphrams, the external fuel filter, and all of the fuses. I have replaced the spark plugs; checked, cleaned, and reconnected every connection with dielectric grease. The RAVE valves are clean, and there are no obstructions in the exhaust.

I am looking for some advice on where to look next. I appreciate any help you can provide.

 

[kustomkarl]

What is the compression of the engine? The lack of good compression will act like this as it will not have the proper compression to recover from the added resistance of the waves. If the jet pump is allowed to come out of the water and loose some of the resistance it will rev back up and gain more speed. Here is some info on a compression check;
You'll need a compression tester. Go to Auto Zone. I think they sell for like $25.00. The compression gage, will screw in the cylinder head in place of the spark plugs. To test compression, remove both spark plugs. Place spark plug caps on the plug cap studs near the cylinder head to ground the empty caps. This completes the circuit of the ignition electrical system and prevents any electrical problems from the caps being un grounded. Using the correct adapter for the threaded end of the tester,( same length of the spark plug threads length)screw in the tester in one plug hole. Hold the throttle wide open. Push the start button. Watch the compression gauge, when it peaks out at the most compression, let go the start button. Read the psi number. I would do it 3 times to be sure it is accurate. Check both cylinders the same way. The ideal compression is 150 psi per cylinder. If it is less, it's not a problem as long as they are close to being the same. If the psi is less than 90 it might need be time for a tear down and a rebuild. If the psi in 1 cylinder is say 140 psi and the other is 80 psi you need to tear down and repair. This difference is a lot and there is a problem. I hope this helps you.

Karl

 

[gpshogan]

Check

Yes, I say you do a simple compression test.

Also, I would reccomend that you at least look at the wear ring and impeller.

Just look underneath into the intake grate with a flashlight.

 

[pgway]

Thank you for your replies. The intake grate and wear ring clearance are fine. I will check the compression and post the results. I appreciate your help!

 

[pgway]

Karl,

The compression in the front cylinder is 90 psi, and the rear cylinder is 85 psi. I guess it sounds like time for a top end rebuild. Is there anything else I should consider for the botton end?

 

[kustomkarl]

It shouldn't need anything in the bottom end if it is just the compression that is low. If it got hot and seized than you would have a bigger problem. Go and check out the "Parts" link we have at the top of the forum for what you need. The prices through the seadoo forum have been very reasonable. Of coarse you'll want to get the cylinders honed out first, then rebuild it.
Do you have a seadoo shop manual? If not here’s an idea for you. You could join as a "premium member". As a premium member you can down load a authentic seadoo manual from the seadoo manual library. In the library is a variety of manuals for almost all years and models. You can view as many as you like on line as a PDF file, or download it and print it for your personal and private use. There are operator manuals and repair manuals for you to do your own repairs on your seadoo. The repair manuals have everything from troubleshooting, repair procedures to winterizing. It contains wire diagrams torque specs and pictures for disassemble and assemble instructions. In the spec sheets it tells everything needed to maintain oil changes, spark plug gaps, carburetor rebuilds and impeller wear ring tolerances. Click on the "Seadoo Manuals" link at the top of the page for more details. If you need any help or get in a jam, we are always here to answer your questions too. Premium members get priority when it comes to getting quick detailed answers.


Karl

 

[Ultra44rk]

Had the same problem on our 1996, it ended up being the rectifier. $65 dollar part, but is a pain to get to. Runs great after install.

 

[steve10391]

I beleive you have double troubles. First of all your low compression problems wouldn't be affected by waves or bumps. Sounds to me like you have a loose wire in the system causing your engine to lose spark on one cylinder. I would take a close look at the coil. If you have an ohmmeter you can check the primary and secondary resistance. The coil has 2 primary connections and it is possible that the connectors are loose there. Also make sure that all the ground wires attached the coil are clean and free from corrosion. Better get that top end off before you have a major on your hands. Hope this helps. Steve

 

[JPX]

You can yank the spark plug boot off the wire and check for corrosion at the tip of the wire. Clip a 1/4" or so off. Reattach the boot to the wire and ziptie it on real tight. Better conductivity from the wire to the boot (and then the plug) will limit intermittent spark loss.

 

[pgway]

I have decided to go with a short block rather than rebuilding the top end. Mostly because of the additional downtime involved in the rebuild. However I do not expect the short block to address the power issue.

I have double checked all of the connections on the coil, and the spark plug wires are good. Another post said a new rectifier repaired a similar issue. Should I try that? Is there a way to test my existing rectifier before I purchace a new one? I appreciate any other advice.

Thanks, guys.

 

[timmyboy76]

Check the volts at the battery while ski/boat is running..14.5-ish. while downtime, can look at it, if a clear/yellowish face toit, then look to see if any burnt marks, also

 

[pgway]

I finished installing the new short block this afternoon, and the XP runs fine on the garden hose. I replaced the rectifier as well in hope it was the cause of my power issue. I will water test tomorrow. I am not looking forward to the ten hour break in, but oh well. I will post the status of the repair.

 

[kustomkarl]

That's great news...keep us posted on your progress.

Karl

 

[pgway]

The ski ran great yesterday. I ran for about 2 1/2 hours and not quite 1/2 tank of gas. The power issue seems to be resolved. I don't know if the new rectifier repaired the problem or if it was something else I did with the machine torn down. Regardless, I am back in business ready to enjoy the rest of the season.

Thanks to Karl and everyone else who contributed.

Please see my new thread regarding a power trim issue on my '95 XP.

You guys have been a great help! Thanks again.

 

[pgway]

I guess the new rectifier didn't solve my power issue. I now have enough hours on the new short block to use full throttle. While riding yesterday the same condition reappeared. It did now show up during break-in, but I was never over 3/4 throttle. I have double and triple checked EVERY connection on the boat. I'm to a point where I am ready to start just throwing parts at it. Does anybody have any Ideas on where to start? I appreciate all of your help!

 

[derek]

carbs or fuel lines. try on reserve. shoulda done the filters in carbs while they were off.

 

[pgway]

I have checked the internal filters in the carbs, the diaphrams, the external fuel filter, and all of the fuses. I have replaced the spark plugs; checked, cleaned, and reconnected every connection with dielectric grease. The RAVE valves are clean, and there are no obstructions in the exhaust.
[/QUOTE]

Carbs, internal filters, and fuel lines are fine. I have not run on reserve. I will try that. Thanks for the input

 

[kustomkarl]

Is it possible that this is a different problem...Give us the symptoms of the problem you have now, so we can diagnose it for you.


Karl

 

[pgway]

Karl,

Thank you for your reply. The condition is the same as when I started the thread.

When I start to ride it will run well until I hit a decent size wave. It will then not let me go over 30 mph until the next wave when full power resumes. In rough water it goes through this cycle wave after wave. In calm water I can travel for miles at full throttle and have no loss of performance.

I am just not sure how to proceed with this.

I appreciate your help.

 

[pgway]

A neighbor said he had a similar problem, and it turned out to be the dess key. The key starts the machine fine. Could this be the cause of my cutting out problem?

 

[pgway]

I have just been out for 45 minutes. I have used both keys...no difference. I also ran on reserve for about half the time-also no change. It seems it must be a bad connection somewhere. I'll keep looking. Anyone, please let me know if you have any thoughts. I appreciate your help!

 

[pgway]

Here are some observations from my outing yesterday. The '97 XP does not start losing power until it is completely warmed up (maybe 10 minutes). The power will come back if I back off the throttle or hit a wave. In calm water I do not have the problem. Everything runs great as long as I stay below 3/4 throttle.

I appreciate any thoughts anyone has!

 

[timmyboy76]

hey...bummer to hear your woow....recheck the compression, then, you said carbs are good, but I'd go thru them again, and is the RV at right time..147*opening...good luck