looking at a 98 spx, what how much compression should i look for?

[yogi24m]

Im looking at a 1998 spx. The engine is all original and the ski is in good condition. I wanna test the compression before i buy it though, how much should it have? What else should i look for on the ski? thnaks

 

[JESSECONSOPOLUS]

my mechanic said 160. i bought my gsx it had like 165 when i tested it. i dunno if engine matters or not as far as compression goes......is it a 787?

 

[robin savell lloyd]

In my opinion the ski should have at least 125 psi at the lowest on both cylinders and you should allways test ride for at least 45 minutes be for you buy so that you can see if it has other issues. :cheers:

 

[JESSECONSOPOLUS]

haha ride it like u stole it, robin u da mandingo!

 

[JJLee138]

In my opinion the ski should have at least 125 psi at the lowest on both cylinders and you should allways test ride for at least 45 minutes be for you buy so that you can see if it has other issues. :cheers:

Good advice. I just bought the XP in my avater and only rode it for 5 minutes or so since it was approaching dusk by the time I was able to get it in the water. Everything checked out great! Well on my 1st day out with it I almost locked up the engine at about the 40min mark due to the hull being nearly FULL of water. Caught it just an inch or two below the carbs and it appears the starter was all that got fried. We'll see after I replace that starter. A sloppy thru hull carbon ring was at fault for the leak.

 

[tomcat&family]

I have heard/read that 150psi in both cylinders is about perfect.

 

[kustomkarl]

Here is some information on a compression test;
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.

Hee is a good link for buying a used seadoo; http://www.seadooforum.com/showthread.php?t=134

Karl

 

[yogi24m]

thanks

sounds good guys, will check those things out, i would like to take it for a ride but there is no lake close. It looks very clean and i can tell the engine has never been apart. Im getting it for $1900 so i figure thats not bad for a 98 spx 800 w/ a nice trailer and nice seadoo cover. what do you guys think?

 

[tomcat&family]

How many hours are on it?

The NADA value for that boat with a cover is $2,500 for the low price and $2,800 for the average price.

 

[yogi24m]

hours

about 25 hours a year

 

[kustomkarl]

The average use is 100 hrs a year...so 25 is low.

Karl

 

[tomcat&family]

The average use is 100 hrs a year...so 25 is low.

Karl

Really? I heard that 20ish hours was normal for the average year. That's what my Sea-Doo dealer told me, anyway.