2005 Rxt Won’t start after running for a while

[AircraftDoc]

Yeah I’m just lost at this point. I need to do a leak down test to make sure. And btw original 115 of pressure test was cold. It went up to around 128 when I re did it warmed up. The only time I was able to turn it on after running was when I took it out of the water the same day. So I’m going to test that again to make sure it’s not a fluke. It would sit tied to the dock for 6 or more hours and that’s all it needed. It’s gotta be a slow leak somewhere I’m sure

Ok, I think I know what happened.
We had a member who had water in his engine after he let his Doo tied up a boat dock. He had the nose pointed to the shore. The wake and waves from all boats cause a hydraulic pump into the back of the ski - same as if you towed it. And you can't tow it unless you pinch off the innercooler hose.
You might be ok unless you ran while it was hydro-locked.
Good luck.

 

[Digdog]

Ok, I think I know what happened.
We had a member who had water in his engine after he let his Doo tied up a boat dock. He had the nose pointed to the shore. The wake and waves from all boats cause a hydraulic pump into the back of the ski - same as if you towed it. And you can't tow it unless you pinch off the innercooler hose.
You might be ok unless you ran while it was hydro-locked.
Good luck.

I don't see how water can get into the engine this way? Just sitting with waves lapping against forcing water through the intercooler into the engine? There is no way as when the ski is running this system is under lbs of pressure and it's a sealed system, the only way you can get water in the oil is a leaking intercooler or its getting in through the intake or the pvc vent is not working. On automotive engines if the oil does not heat up this can happen also, so if your engine is temperature regulated you might want to look at that. Another check is to take the coolant cap off and run it and see if any bubbles show in the reservoir tank, that would eliminate a head gasket leak. I would say the fact he has water in the oil and it won't start points to plug fouling and failure due to moisture in the intake system. Even if the engine has low compression on one or more cylinders the numbers shown as tested the engine would still run.

 

[AircraftDoc]

Ok, I think I know what happened.
We had a member who had water in his engine after he let his Doo tied up a boat dock. He had the nose pointed to the shore. The wake and waves from all boats cause a hydraulic pump into the back of the ski - same as if you towed it. And you can't tow it unless you pinch off the innercooler hose.
You might be ok unless you ran while it was hydro-locked.
Good luck.

I don't see how water can get into the engine this way? Just sitting with waves lapping against forcing water through the intercooler into the engine? There is no way as when the ski is running this system is under lbs of pressure and it's a sealed system, the only way you can get water in the oil is a leaking intercooler or its getting in through the intake or the pvc vent is not working. On automotive engines if the oil does not heat up this can happen also, so if your engine is temperature regulated you might want to look at that. Another check is to take the coolant cap off and run it and see if any bubbles show in the reservoir tank, that would eliminate a head gasket leak. I would say the fact he has water in the oil and it won't start points to plug fouling and failure due to moisture in the intake system. Even if the engine has low compression on one or more cylinders the numbers shown as tested the engine would still run.

The engine coolant system is separate from the inner cooler. The inner cooler cools the air after the SC.
Water enters from the pump into the inner cooler, then the water exits through the exhaust manifold. If the engine is not running, there is nothing stopping water from entering through an open exhaust valve and into the one of the cylinders -- Water in the engine.

 

[Digdog]

The engine coolant system is separate from the inner cooler. The inner cooler cools the air after the SC.
Water enters from the pump into the inner cooler, then the water exits through the exhaust manifold. If the engine is not running, there is nothing stopping water from entering through an open exhaust valve and into the one of the cylinders -- Water in the engine.

Wow I never would have thought of that! Good post for others who store their skis in the water, thanks!

 

[AircraftDoc]

Point the PWC outward.

 

[IDoSeaDoo]

actually, on these 4tecs, the valves are all closed when the engine is shut off. I don't understand how, but I have verified it the last time I had mine apart. That doesn't meat a little water won't run down past a closed valve given enough time.

 

[Robert215]

Well I keep it tied parallel with the dock. And I’m also in a canal so the only real wake is from other boaters. But that seems like a solid theory! I haven’t been able to test it yet. I flushed that old oil out 4 times and replaced the filter on the last change. If the ski is towed will water get in the oil that way as well if you don’t clamp that hose off?

 

[IDoSeaDoo]

The way your ski cools itself is there is a hole in the pump behind the impeller (high pressure side) that admits water as it's being forced out the pump. Your jet pump is what drives the raw water into the exhaust cooling system. If you tow your ski and don't clamp this hose, it acts just as if you're driving the ski. At a certain speed, water is forced into the cooling system where it begins to accumulate in the water box. Once that fills, the level continues to rise until goes up the J-pipe and into the exhaust manifold. Once it's sitting on top of the valves, it's only a matter of time before it seeps past and onto your pistons and then down past the rings into the oil.

 

[AircraftDoc]

Well I keep it tied parallel with the dock. And I’m also in a canal so the only real wake is from other boaters. But that seems like a solid theory! I haven’t been able to test it yet. I flushed that old oil out 4 times and replaced the filter on the last change. If the ski is towed will water get in the oil that way as well if you don’t clamp that hose off?

Yes, one has to clamp the hose when towed. 3/4 Hose. Members have placed a 1" PVC valve with 3/4 hose barb fittings inline in front of the engine before the inner cooler. 1" is used so not to restrict the flow. Then wrap the DESS Key around the valve when in the off position so you don't forget to reopen the valve.

 

[IDoSeaDoo]

Yes, wrap key around valve when closed! That is invaluable advice!!! I've lost a brand new top end once because I didn't do this. VERY easy to forget this.

 

[Robert215]

I ordered a couple clamps already just waiting for them to come In! And it won’t harm the hose by clamping it off? And a update on the water issue. Got all the water out of the oil. Ran it 50 miles yesterday. Took it right out of the water. And it turned right on this morning. So there is definitely a issue when it sits in the water for more then a couple hours. Just gotta figure out what. Checked the dip stick this morning too and oil is perfect

 

[AircraftDoc]

What kind of clamp? The OEM in the owners manual?
There is a device that pinches the hose.

 

[Robert215]

I bought it on eBay cause I don’t have a owners manual besides one online.

 

[AircraftDoc]

That looks about right. Should not damage the hose. You could put a shut off valve in the hose.
I just got a harbor freight needle nose vise grip and wrapped the teeth with electrical tape.

 

[susanmac]

So I have a 2005 RXT. Last week ran it 20 miles and a couple hours. Got home. Wanted to go back on for a evening ride and it would try to start but just couldn’t. Checked battery just to eliminate that. Battery was good. So changed for new plugs and now it turns on. Took it about 20 miles shut it on and off out there and it’s perfect. Next day I try to start it, it wouldn’t start. Pulled plugs and the 3rd cylinder plug was fouled. Replace new plugs and still won’t start now. Switched one of the coils from my gtx to the 3rd cylinder coil to see if it was a coil and it still wouldn’t start.I just don’t know what to think could be wrong with it or where to start... any help would be really appreciated!

Make sure that the lanyard is pressed down tight enough while trying to start. One time I wasted an hour that mine wouldn’t start and it just wasn’t on good enough.

 

[Robert215]

believe me it isn’t the key! It will crank and try to start. I’m just wondering how water can leak all the way in there and cause the plugs to get wet..

 

[susanmac]

So I have a 2005 RXT. Last week ran it 20 miles and a couple hours. Got home. Wanted to go back on for a evening ride and it would try to start but just couldn’t. Checked battery just to eliminate that. Battery was good. So changed for new plugs and now it turns on. Took it about 20 miles shut it on and off out there and it’s perfect. Next day I try to start it, it wouldn’t start. Pulled plugs and the 3rd cylinder plug was fouled. Replace new plugs and still won’t start now. Switched one of the coils from my gtx to the 3rd cylinder coil to see if it was a coil and it still wouldn’t start.I just don’t know what to think could be wrong with it or where to start... any help would be really appreciated!

Make sure that the lanyard is pressed down tight enough while trying to start. One time I wasted an hour that mine wouldn’t start and it just wasn’t on good enough.

You were right. Thanks!