1997seadoo gti

[danny 97 gti]

i have a 1997 seadoo gti that runs fine o n trailer but put it in water its hard to start.when it cranks it will run fine at half to full throttle.it will not idle when in water but will on trailer. runs fine when on hose.fixed leaking exhaust, new heli coils and new gasket. cleaned carb.and new fuel pump diaphams.also new carb gasket..when it does run in water it runs for about 10 to 15 min.

 

[OVRAT]

repeat offender

I have a 97 GTI that has similar issues. I thought I had carb issues (still may) but I noticed that I was getting exhaust gas in the cooling system. Check and see if you can feel air coming out where you hook the H2O hose up. If you do pull the inlet / outlet / exhaust lines off of the cover on the head. If you feel air coming out, the internal top O rings around the spark plug bosses are bad (at least). Further eval on the rest of my top end rubber was bad. Compression was running 90 psi with bad rubber. Now that I have gotten into it, I could see where this could be a common problem. Replacing the top end rubber is not that involved. However, be prepared to find that corrosion has set in the bolt bores and may make removing them a little harder. Use plenty of PB blaster and a 12 pack of patience. I stopped short of pulling the cylinders. I just got a bottom tap to clean the bolt bores before putting it back together.
My ski ran fine out of H2O. Would run in H2O but was hard to re-start some times. Just another angle.
OVRAT

 

[kustomkarl]

A compression check would be a good idea.
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