1973 25 hp

[jr43]

Hi I just got a 25 hp it starts and runs good shifts good. when i run it there is a oil/water mixture coming out of the side of exhaust housing this normal or a problem. also decided to change impeller and there is carbon build up on water tube and top of pump is this normal with this older motor. also i have 63 18 hp wil not hold a prime at low idle changed every thing from gas tank to carb. fuel lines and impulse. didnt mess with diafram runs good at higher rpms.is this a low compression issue it has 95/93

 

[fdrgator]

I don't know exactly where you are speaking of on the oil/water, but yes it is normal for some oil to come out with the spent cooling water. It is the oil that you put in the gas that has gone through the motor and done it's job. Then the part that wasn't burned goes out with the exhaust. The water pump is in the exhaust housing, so black soot/smoke/gunk is normal. On your other motor, if it has enough compression to run on both cylinders, it has enough to operate the fuel pump. In the strict sense of the word, it is crankcase compression that operates the pump, not cylinder compression. But still, if it runs.......