Close call, should I be more worried?

[MHarness]

So here is what happened. Yesterday we put the boat (2015 195HO, 250hp engine w 78hrs) in the water, parked the trailer and as I was walking back to board the boat, the bilge was on pumping out water (Engine was off and I knew 100% I had both plugs in) I immediately got it back on the trailer and out of the water, pulled the drain plugs and let the boat drain. The bilge ran steady for another minute. The amount of water was substantial. This was not from rain, as I keep the plugs out and it's stored inside.
With the boat out of the water on the trailer, I cranked the engine over quickly to make sure it would start. Immediately heard a 'clunk' and then ran smooth and sounded completely normal. I turned it off only after a few seconds.
My next idea was to keep the bow hook attached to the trailer, back it back in and watch the engine compartment to see if I could determine where the leak was.
Got it back in the water and.... no leak....?!!? We cautiously had our day on the lake, boat ran great, did a few hot laps, floated at the sandbar, pulled kids on the tube, .. zero issues, (except my anxiety from the leak that would have sunk the boat had we not gotten it out of the water)

My theory:
Earlier in the week, I pulled the jet pump to inspect. Everything looked good, impeller didn't show damage, and wear ring was fine. Good amount of grease in the nose cone with zero signs of water intrusion.
I re-assembled the jet pump.
I believe what may have happened was that the splines or 'teeth' of the driveshaft were not 100% aligned with the impeller during reassembly. That 'clunk' I heard when I started it, was the splines aligning. This then caused the rubber boot to properly seal, eliminating the leak.

Do I need to pull the jet pump again to inspect the driveshaft? If my theory is correct, and water was getting in past the rubber boot connection of the impeller and driveshaft, will I need to re-grease this connection? I did read some forums on similar issues, and some were talking about hot water in the ski compartment. I did have hot water but am contributing this to water being in the bilge, (too low to cause it to turn on) under the engine getting heated, then when the boat is 'level' that water returns to the bottom of the ski locker.
We are going to the lake for our summer vacation in 2 weeks and our main entertainment is the boat.

I have time to rush in some parts for maintenance, but not sure my next best course of action.

Thanks all!

 

[Luc Lafreniere]

1. That impeller boot does NOT contribute to water going into your boat. The actual seal is called a carbon seal which is at the other end of the drive shaft where it enter the fibreglass bill. The impeller boot is attached only to the impeller. Many don't even have installed and they don't sink.

2. If the carbon seal leaks, you can sink the boat very quickly. But based on the fact you sent boating and had no issues, I don't think that's where you're leaking from. But if the driveshaft wasn't aligned correctly, you could have put pressure on the carbon seal which allowed water in. Maybe it settled and fixed itself before causing more damage? But I don't think this is likely.

3. Lots of water can be trapped in the ski locker. When you lower it on the ramp, water can make its way back to the bilge very quickly. I'm suspecting this is all that happened in your case. But this is based on very limited info.

4. If it made that sound, I would inspect it yes. It shouldn't make that noise. I'd make sure you didn't break any splines or other in the process.

 

[MHarness]

Thank you, Luc.
Good to know that a bad impeller boot does not cause water intrusion.
I'll pull the jet pump again and inspect the splines.

Possibly a drain plug was cross threaded? Although I have a hard time believing that much water could enter so quickly.
I hate not knowing, it will be a long time before I will be able to fully relax.

 

[Luc Lafreniere]

Consider doing the classic reverse leak test. Disconnect the bilge from the battery. Close the plugs and then start filling the bilge with water. Look under the boat for leaks. It shouldn't.

If it doesn't, then start the boat for a few seconds without hose cooling. It's fine to run it without cooling for say 10 sec.

And immediately after someone else starts it, look by the drive shaft entering the hull (grate area) to see if any water comes out. That last test confirms your carbon seal is good or not. Make sure the water covers the carbon seal area inside the bilge. It should be completely submerged before doing that last test.

I'd also double check for any loose hoses. Pull and tug on them. Pay special attention to the exhaust cooling ones or intercooler ones. Where the fresh water circulates.

All of that should give you some reassurance or confirm the problem if any.