2012 242LS - Starboard Vibration - bearing?

[zmachines]

Hoping to find some help/guidance after reading though all what could be an issue.
Background: Fresh water only 2012 242 LS boat. Purchased boat in August of 23. 240hrs on motors. Previous owner replaced intermediate bearings, impellers, and wear rings for both engines. Said he had bad cavitation and low on top end speed. When we met, I took the boat for a 2-3hr test ride with him, and all felt good/fine from what I could tell (my first jetboat).

Last summer around this same time we starting to notice a whine in the starboard side motor. I thought maybe intermediate bearing installed issue from his work and check grease levels, continued to monitor (and read up on potential causes). Noise increased on next two outings with a rear bearing failure. I pulled the jet pump and found water in the nose cone along with the destroyed bearing. I replaced all moving parts and orings/seals including a new nose cone just to be safe. After the repair we took it back out for a test ride and things were quiet and ran smooth. The starboard "assembly" always seemed to be slighter louder than the port side (Trying 1 motor at a time at very low speed).


This past weekend almost a year since last time, we heard the same whine coming from the starboard side again. We may have put 40 hours on the boat since last summer (lake life to the beach area is a short distance for us). I am at a loss of what it could be. I suspect when I pull the pump and open the nose cone, I will find water in the bearing assembly again and need to tear down replace the same parts.

Again, the one difference we both notice from port to starboard (when I first purchased and after my repairs last year) is a slight difference in sound. Port is quite, maybe a vibration on starboard side that gets worse and allows water in, I'm not sure.

I want to correct the problem the right way, but unsure where to look now. Any ideas? - Michael

 

[zmachines]

Any thoughts?

 

[anmut]

Thoughts:
Same nose cone letting in water and ruining the bearing...

1. Did you use correct grease when refilling the bearing?
2. Did you install a new o-ring on the nose cone?
3. Did you inspect the nose cone for any damage?

 

[Neutron]

Any thoughts?

Yes first verify there is in fact water in the cone, if there is you need to find the source of the leak. Bad/cracked housing. Incorrect assembly, bad seal, etc....

 

[zmachines]

Thoughts:
Same nose cone letting in water and ruining the bearing...

1. Did you use correct grease when refilling the bearing?
2. Did you install a new o-ring on the nose cone?
3. Did you inspect the nose cone for any damage?

1) yes, purchased the spec grease
2) yes, new o-ring, carefully not to pinch during cone install.
3) yes, new cone just to make sure and was a clean machined surface where o-ring sits.

I’m OCD on repairs and took my time. Not to say I couldn’t have made a mistake, but I like to take my time on repairs like this since I don’t want to repeat it again.

 

[zmachines]

Yes first verify there is in fact water in the cone, if there is you need to find the source of the leak. Bad/cracked housing. Incorrect assembly, bad seal, etc....

100%, I need to pull the pump and start inspecting, just know from the sound I’m expecting the same thing again. Should have the time this weekend to tear it down.

 

[sunbyrned]

I have the same boat and have had no problems related to your issues. For the original owner to have to replace the intermediate bearings, impeller and wear ring with such low hours makes me think he/she rode it for a good bit of time with something stuck in the pump. When you pull the impeller this weekend, check the condition of the splines that go into the intermediate bearing and look for any possible grinding. Wonder if it’s an alignment issue. Another thought is, if they replaced those things, are the intermediate bearings universal? In other words, do they fit all impellers? I don’t know but just a thought. Be sure to grease the splines. Maybe that will help a bit. I’m hoping there’s no water in the cone again to help you narrow down the problem.