2002 GTX DI (951) Water Drowned - Not not running correctly

[kmclaugh]

Hello all,

I bought a 2002 GTX DI (951) a month ago. I took it out to the lake, it ran exceptionally well. Hit 55mph easily, we had a blast. We put 2 solid hours on it that day. The next morning we hit the lake for 30 minutes before we went skiing on the boat. When I came back to the dock my jet ski was a foot lower in the water. My engine was completely underwater.

I pumped the water out and found the leak. A water hose came loose and allowed the engine compartment to fill up with water. I fixed the issue but in the process I cranked the engine (mostly out of ignorance). I then read how to recover from a water drowned engine and noticed I screwed up.

Anyway, I got the jet ski running again but I found water in the back cylinder. I tore the engine down and replaced the cylinder block gasket and the head gasket (along with several other gaskets and o-rings) As well as the piston rings. I started the engine and it ran very well. I connected the hose and turned the water on and it ran extremely well. No misses, no issues at all.

I took the jet ski out to the lake and put it in the water. The jet ski wouldn't go above ~2200RPM and would spit and sputter. Something else was wrong. I pulled the spark plug cable off the front cylinder (while in the water) and the jet ski ran the same, spitting and sputtering. I then put the spark plug cable back on and took off the rear cylinder cable. The jet ski wouldn't start at all. I figured it's because it only idles on one cylinder?

I put the spark plug wires back on and started the jet ski again, same thing. I then pulled the plug out of the first cylinder and smoke shot out. I've never seen that before but am assuming this is normal?

Does anyone have any advice for what to do next? I cleaned the rave valves, they are fine and appear to be functioning correctly. I've read I may have broken the reed valves. Could this be the case? I'm really lost on what to do next.

 

[mikidymac]

If it runs and you got the water out of the engine then it sounds like something electrical got wet. I would check all electrical boxes and plugs to make sure everything is clean and dry.

 

[Coastiejoe]

I tend to agree. Something is partially shorted or still has water in it.

I would do a compression test just so know where your base engine is.

 

[kmclaugh]

Thanks! I ran a compression test on both cylinders last night. The front cylinder is at 120 PSI and the rear is 128 PSI. I also removed the front spark plug and left it plugged into the cable and turned the engine (I know it's unsafe but was very careful). The spark across the spark plug was very good.

 

[kmclaugh]

I've read the compression should be around 145, is this true?

 

[Coastiejoe]

The 951 is lower than the others. So 135-140 is very good on the 951. 130 is perfectly fine. Compared to 150 on the 700 series blocks.

 

[kmclaugh]

Ok, I think I was simply expecting it to be close to what you get from a new engine since I replaced the rings last week. The cylinder walls looked great, in fact you could still see honing marks in it.

 

[tkarvelis]

The di is higher from what I was told. Compression is still marginal at 120... 128 is slightly better.

 

[tkarvelis]

If the rings have just been replaced, it will take some time to break the engine in, and set the rings.

 

[jhjesse]

Probably hasn't seated the rings yet. I wouldn't be too concerned with that. As above check and clean all electrical connections use dielectric grease. Do a voltage test after by putting a volt meter on the battery and cranke the ski. At 4000rpms you should see 13.5 to 14.5vdc. Anything below 13 any you need to replace the rectifier.

 

[Coastiejoe]

As the rings "seat" it should help with the compression.

 

[kmclaugh]

Thank you everyone for your suggestions. I ended up taking off the intake's and pulling out the reed valves last night. The rear reed was perfect. The front reed had one vane completely missing and the another was sticking straight out. Also, one of the aluminum "edges" we're broke as well. I'm sure this is my problem. I'll order new reed's and cage and hopefully will be back up and running.

I've heard the engine will simply "eat" the reed with no issue. What about the small piece of aluminum which was broken off? Was that eaten also? Should I tear down the motor? The engine probably has an hour on it since this happened so if there was any damage I'm sure it's already been done.

 

[jhjesse]

Glad you found the problem. Good luck.

 

[mikidymac]

What aluminum "edge " are we talking about?

 

[kmclaugh]

 

[kmclaugh]

Do you think this will cause a problem?

 

[jhjesse]

Yep you found it.

 

[68ragtop]

One of the many potential problems with water ingestion. Even with the spark plugs out, whatever is in the bottom of the case gets compressed on the downward stroke of the piston. No place for the water to go, so it takes the easiest/weakest path. Pretty good chance that broken section of the cage went back into the engine & did some damage somewhere.

 

[mikidymac]

I would have a hard time sleeping knowing that piece might be somewhere in my engine.