Sand in lower unit?!

[G8trbait]

I have a 2003 90 HP ELPTO on an 1860 alumacraft tunnel hull. I bought the boat and replaced the water pump housing/impeller in August. I noticed that there was a good amount of sand in the lower unit, but none in the water pump housing/impeller. I cleaned it out and have used it almost every week. I decided to check on the health of my impeller and dropped the lower unit last night. To my surprise there is more sand. Again, in the lower unit but not a noticeable amount in the impeller/housing.


So I assume it can't be a good thing since that would mean salt water is getting in the unit and could rust it from inside out? I also saw a small pin hole in the very front in/leading face of the lower unit??!! I'm at a lost. All advice will be greatly appreciated. Thanks.

 

[andrewddrennon]

Re: Sand in lower unit?!

Do you mean on top of the lower unit??? Or there is sand in the gear lube? The only to know if your lower unit has sand in it is to drain the gear lube and look at it.Im going to assume you mean there is sand in the pockets around the water pump which is not inside the lower unit but just sitting on top. Which is perfectly normal if you run in shallow water alot. That will wear out your water pump faster though.

That pin hole is most likely perfectly noraml, most mercury lower units have a passageway for the speedometer machined in them. That hole is where it starts.

Do you know how to check your gear lube?

 

[G8trbait]

Re: Sand in lower unit?!

sorry for the lack of description. Yes in the pockets around the water pump and not in the foot oil. Does it come in from where the lower unit is bolted to the motor or is it coming in from the water pickup and then slipping out of the gasket in the water pump housing?

 

[andrewddrennon]

Re: Sand in lower unit?!

Your prop is kicking up the sand in shallow water and its coming in through the shift shaft hole most likely......not a big deal at all with the ones iv seen ....clean it out and try not to run in shallow water. The area outside of the water pump is always full of water, its not sealed off. If your prop is kicking up sand ,which is indicated by the settled sand, your water pump is picking some of that up which will make it wear out faster.

The only option I see to keep sand out is not run in sandy shallow water. Pick up screen will block most of the sand before it gets to the water pump but not all. Im not saying your water pump will fail tommarrow if your kicking up sand, but you wont get as long of life out of the impeller. Id say change it every year.

 

[G8trbait]

Re: Sand in lower unit?!

cool thanks for the help