Compression numbers.

[lucky68]

Just picked up 2 nice seadoo for a really good deal. A 06 gtx and 08 gti155. Gtx has 175 compression all the way across. The gti has 175,175,141. But it seems to run fine. Does the one lower number on the gti seem like a major problem.

 

[skiasylum]

You can learn very little from a compression test on a Seadoo. A leak down test is what is recommended and is used to diagnose engine problems. Get yourself a service manual if you don’t have one and read up on engine trouble shooting. If both your engines are running good with good power and and wot rpm you should be good. Just pretend you never did the compression test. If you can’t do that do a leak down test on that engine would be appropriate.

 

[MacSeaDoo]

You want to do a cheap compression or leak down test? Figure out from what the typical WOT top speed is and associated RPM for your machine. Go run it WOT and figure out how close your machine is to those numbers. If it is within a few MPH, you don't have a compression or leak down problem.

 

[lucky68]

Yeah had it out yesterday. Wide open rpm was 7400rpm and gps 54mph. But it had a bad wear ring I just replaced, so mph might go up a little.

 

[MacSeaDoo]

From what I read, you should be able to hit 60-63 mph at 7500 rpm

Hit near those numbers and you are most likely making 185HP.

 

[lucky68]

Mines only a 155hp. It's not the super charged one.

 

[MacSeaDoo]

Sorry I misread your post and thought the issues were with the GTX.

Your GTI 155 should be able to hit 58-60 mph.

 

[sktn77a]

The gti has 175,175,141.

I'd be concerned about the low compression on one cylinder. Usual acceptable variation is 5%-10%. Yours is almost 20%.