well the motor will like it, it will run cool but the power bill will be high. it will not have the flow of a 2hp impeller
The water pump impeller on a 7.5 hp Mercury outboard, is located on top of the gearcase, and is driven by the driveshaft.
If the sound is more like a very loud growl it may be the bearings within the motor. If the motor is less than 1.5 hp or 2.0 hp - replace the motor. You might have to get down next to the pump to determine if it is the motor or the impeller at or right behind the pump pot basket area. If it sounds like the later area it could be that the impeller has debris in it or that may be coming off the shaft. A pool repair tech would know almost immediately. If it is debris in the impeller, that would be the least expensive way to correct. A fairly simple job. Ken
This is how to fix the impeller on a Chrysler 25 HP outboard motor. Disconnect the coupling that's on the outside of the leg, flip the housing and twist in impeller.
18-3085 sierra
Changing the impeller on a Johnson 70 hp outboard motor requires pulling the power head and disconnecting the engine. Once this is done, an open end wrench can be used to first loosen the fitting before removal.
Put a 12 hp motor on it.
Most pump impellers rotate off in the opposite direction as turning under power. So rotate the impeller anti-clockwise to loosen it. The real trick is to grasp the impeller hard enough to turn it without warping or bending it. There is almost always a screwdriver slot at the other end of the shaft to hold it from rotating as you remove the impeller.
The impeller is located in the lower section of the motor near the prop. Take the two nuts off and the lower unit will separate from the top. Remove the O ring and the seal from the long shaft before removing the two nuts from the water pump housing. Good luck removing the impeller itself. I had to cut the soft brass ring with an oscillating tool. A paint can opener also helped in the removal.
what causes a boat motor 40 hp to stall when it is put in gear
Annually
Below 2.0 HP is not cost effective, specially if the motor is over 5 years old.
1 HP electric motor = 1.5 HP hydraulic motor so for a 3 HP electric motor you would need a 4.5 HP hydraulic motor. Also for your information a 1 HP hydraulic motor = 1 2/3 HP gasoline engine.