Carbon seal leak - what are your thoughts

[Charliem]

Last weekend first ride of the season. Heading south for about an hour in bay noticed boat was slowing down need higher RPMs to maintain 30 MPH. Turned around headed to my lift the last 30 mins back had RPM 6500 and 20 MPH. Got back opened plug in back of boat and with bilge running water ran out for 1 ½ hours. Boat was filled with water after draining water, went for quick ride noticed water coming in at the carbon seal on star port engine. Boat is now at the dealer, he called and said the impeller came loose and push the drive shaft forward. Causing the engine to go out of alignment and destroying the seal. Now he is said needs to pull engine to open bottom crankcase to check main bearings and possibly a new block. Claims if I do have him check bearings the engine can blow apart at any time. Does this sound correct? Or my idea is I know I did not have the back plug out over the winter and water froze at the seal.



Questions:
How can an impeller back off? The engine turns one direction and the impeller turns on the other. I thought the impeller would tighten more because of the directions.

If so much forward pressure on the drive shaft one would think the pump would go out first. Correct?



Thanks!

 

[Coastiejoe]

I would be getting a second opinion. For the motor to be PUSHED out of alignment would take some pretty good forces. The Carbon seals fail. Sometimes it is the O-ring retainer (now replaced with a C-clip). If it were mine, I'd politely tell him you are taking it home to think it over so as not to burn a potential bridge. But,,, I'm saying he is wrong or lying...

 

[devonte007]

I agree 100% with coastiejoe, it would definitely take some significant forces to dislodge the engine from its mounts - granted everything was tight to begin with. I suppose it is possible the jet pump could have come loose from the boat and the driveshaft could have become misaligned as a result but I have never heard this happening.

If something like this did happen it would cause some fairly significant vibrations while under power. So much so that you probably would not feel safe to continue running the engine. If you did run the engine with this significant vibration and shaft out of alignment I suppose after a while it could cause damage to parts of the lower engine. It doesn't sound like this happened though.

As coastiejoe mentioned, much more likely the c-clip or something similar came loose. Not sure how mechanically inclined you are, but if you take the drive system apart and upload some pictures we can probably help you figure out what went wrong and how to fix it. Otherwise ask around and try to find someone else more knowledgeable (and trustworthy) to take care of this for you. I'm sure there are some forum members in your area who could direct you to a new dealer...

 

[Coastiejoe]

I will second the NOISE and VIBRATION aspect. You would have KNOWN FOR SURE that something serious was wrong.