2003 STX-12f

[leejax01]

Could it be the water box? I tried to get it off as it has a small pin hole leaking, but the thing must be corrosion welded on at the hose coupler to the exhaust. Maybe the previous owner put it up wet and left water to corrode thus restricting the exhaust flow and clogging some water taps?

[smokeysevin]

Curse me for not giving my usual 3 things, check fuel pressure, check compression, and look for exhaust leak. I have a hose if you are interested. That is probably it. Fix the cooling issues and fix the exhaust. These skis are known to run like shit even with a small leak and your simptoms are consist ant with that.
Do you run the engine on the hose with the seat off?
Sean

[leejax01]

Did check the cooling system and found the cooling nipple under the water box inlet full of corrosion.



I believe it comes from the water rail under the intake. That may be what was going on. Did not have time to water test it today, but will do my best to go Monday after work. I checked and may be able to rent a fuel pressure gauge if that isn't the fix. When you mentioned exhaust leak, I assume by the exhaust manifold or in the water box? Reason is I also fixed a leak in the water box neck that was causing water to leak out into hull.

[smokeysevin]

No I mean a small hole in either the rubber couplers for the exhaust or an actual leak in the waterbox. When the ski starts to run like crap pull the seat. If it smells like exhaust that's your problem.

Sean

[leejax01]

Ok. Yes, I rode it twice with the seat off and that is how I found the water box leak. I might be picking up an exhaust manifold as well as a new waterbox as it corroded pretty badly under the rubber coupling and I assume the exhaust manifold may have more issues

[smokeysevin]

Just pull them and check for actual leaks. Those aren't cheap parts.

Sean

[leejax01]

Took the ski out today and had mixed results. First the good news. Was able to max at 48mph and did not go into limp mode. The bad news is that it still seem to choke out at max throttle after some time, but did clear out and was able to ride again at max speed. Still no water out side outlet when on the water, but do get water out the side outlet on the hose.

I did find another hole in the water box needing repair though. I am thinking maybe cooling water inferring into the exhaust somewhere in the exhaust manifold and going out the water box causing it to stuff the exhaust flow and choke out. Then able to clear out and go again until it stuffs again? Either way, will get the fuel pressure gauge and figure out for sure what is being put out there. Any ideas?

[smokeysevin]

You still have a cooling line blocked. The water box will normally have water in it so in the event that there is a leak inside the header it wouldn't make much of a difference. The exhaust leak we are talking about is an exhaust gas leak from either the water box or one of the connectors. That would choke out the motor. If water is getting out then exhaust gas probably is too.

Sean

[leejax01]

I don't know which one then. I started from the pump and worked both ways until back to the waterbox and that is all I found. Weird as the side outlet does get flow on the hose, and it does get some slight flow from the side nipple if I remove the hose going to the outlet.

[Shuswap]

Follow the water flow chart in the manual: 9-8

Water from the hose connection enters the head and has an almost direct link to the pisser....it doesn't appear to be directed elsewhere....if there is a blockage that prevents it from doing so.

Do you get a flood of water dropping out from the exhaust when the ski is run on the hose? As well as from the pisser?

I still think you have a major blockage and the small amount of debris that appears to have come out of the exhaust system indicates that this may be the case.
Did you get the pump filter checked?

I know it's a lot of work, you don't own the ski and you may be getting a little tired of the problem....but there is a issue that can be sorted, given good diagnostics.