Mercury 9.8 impeller

[dirk26]

Last saturday I took my 12 foot valco out on the river. Its powered by a merc 9.8hp. upon leaving the boat ramp I noticed right away that the motor was not quite putting out like it normally does. After about a minute of it running I turned around thinking maybe i need to adjust the trim cause i shifted some weight around in the boat a couple days prior. Upon turning around I noticed the engine was not pumping water so I shut it down right away and paddled back to the ramp. Took it apart, impeller was shredded of course so i ordered a new one but Im wondering if anybody knows if a shredded impeller would cause an imediate loss in power like that right off the get-go. The motor does not have a thermostat so is it possible that the loss of water resistance in the pump was stalling the motor?

 

[huntin dawg]

Re: Mercury 9.8 impeller

The lack of power was most likely the impending seizure due to lack of cooling. Good thing you shut it down when you did.

HD

 

[dirk26]

Re: Mercury 9.8 impeller

I just hope it didnt do any permanent damage. From startup till shutdown couldnt have been more than 2 minutes and it was about 31 degrees out that morning. Hopefully I put in the new impeller and its all back to normal.

 

[huntin dawg]

Re: Mercury 9.8 impeller

Seizure is not always the end of the world for a small outboard. Usually they will free up when they cool down and asside from scoring on the piston there is little damage. These little motors are tougher than some people think. Have you tried pulling it over since it cooled down? I bet it's still o.k. Wouldn't hurt to do a compression check to be sure before you start it up after changing the impeller.

HD

 

[dirk26]

Re: Mercury 9.8 impeller

Yes i did fire it back up after I got back to the boat ramp (about 10 minutes), and it fired up just fine. Shut it down again right away though cause still no water flow (I was hopeing it was just some ice or mud blockage but it turned out that some steller mechanic that worked on it before I bought it decided to leave an extra drift key inside the impeller chamber). Nice! Oh well, should have the impeller soon and ill be back out there soon, ill keep my fingers crossed.