I need to install a water pump impeller I just bought this boat I think the impeller is dry rotted I found a new one in the boat and also how to install the gear oil in the lower unit and what wieght oil I would be gratefull for any help thanks Jerry

The drive shaft going to the lower unit through the water pump turns clock wise. If installing a new impeller, put a little liquid dish soap on it to lube it. While pushing the pump housing down, turn the drive shaft clock wise and this will seat the impeller in the right direction. Hope this helps.

If it's just the float that is rotted, replace the float with something else, maybe a ping-pong ball?

There are a number of reasons. First of all you are sucking air somewhere if there is not water coming into the pump basket while
the pump is on. If water is not coming into the pump basket while the pump is running then it is not going through the filter and back out the returns. With that being said is it possible that there is a valve closed? Is the O Ring under the pump basket lid dry rotted or cracked? Is the impeller spinning? If the impeller is not spinning freely then there is something stuck in the impeller which can usually be cleaned out with a screwdriver or your fingers as you spin the impeller manually. There could also be something like a pine cone or any object bigger than the pipe you have which is probably 2" pipe stuck or lodged and not allowing the water to pass. This usually happens in the skimmer line. You can try closing your skimmer valve and just running the motor off of the main drain. If the pump works you know that is your problem. Swim Time

I’m happy to help further over the phone at https://www.6ya.com/expert/brandon_156682b88afabb53

I would think 2 things.. one at each end.. and did you lightly grease this up during install? reason I say this is starting this dry is not good.. that rubber gets hot and starts wearing imediately.. also check the ports for any blockage flush as needed..

need to drop the lower unit(prop and all) to acess the chamber for the impeller.. give the impeller a small coating of grease so its not dry when starting up..

Undo gearbox bolts,take off trim tab,undo bolt in trim tab cavity,disconnect speedo tube,pull off gearbox. You will see pump housing,undo 4 bolts,pull off housing exposing impeller,there maybe a clip on top of impeller depending on model,pull off clip then impeller.yamaha didn't make outboards in 75

Pices of impeller could be stuck in block,put hand on top of block and feel if it is running hot,blow compressed air into tell tale and see if that helps

Could be a faulty temperature sensor. May want to replace it. Secondly if you have an old rubber water pump impeller that was dry-rotted and lost a piece, it could actually be lodged in one of the cooling veins of the block itself. This could still allow water to spray from the tattle tale vent but an isolated area of the block could still not be getting the normal flow it should and causing the buzzer to sound out.

I could possibly give you a better explanation if I knew the horse power of the outboard. However hear is what happens to most "tiller" operated outboards. Water pumps are made from a pliable soft rubber which by the way needs water to lubricate it even if you just crank it over to check something, or fire it up for a few seconds on a dry impeller will destroy it. Most often a few pieces will fly off and enter the water cooling system and then lodge in one of the small passage ways blocking water flow. When a new impeller is installed the engine runs pumps water and overheats.

The pump impeller is probably plastic -- if so, dry rot is out.

Most likely the pump shaft is just dry from lack of use. More use will probably wet it enough to stop the squeal.

Charlie