Re: Force 75 impeller?
Rob: First Double check the condition of the battery and cables to rule them out. You would be surprised at how many times a corroded connection will hide out and confuse you. Borrow a known good one. These engines seem to be very difficult to jump start so hook up the known good battery to the engine cables. One trick I use on my battery cables is to use a stainless lock washer both on top and underbeath the connection. The lock washers have a sharp edge which bites into the connector and breaks any corrosion that may be starting.
Next, a little background: A new impeller absorbs around 10-15 horsepower at speed and given this, they are normally a little difficult to turn by hand. If you are trying to turn the prop shaft without a prop, you will not be able to do it. Depending upon your strength, you may or may not be able to turn the drive shaft by hand. If you LIGHTLY fasten on a vise grip over the splines (so you don't **** them up) you should then be able to turn the drive shaft.
Now, the impeller is normally a little larger in diameter AND a little (not much at all) taller that the water pump. So, it is squeezed between the pump housing and the stainless plate. This is to prevent leakage and loss of water. This drag coupled with the bending of the vanes makes it difficult to turn the shaft by hand.
HOWEVER: Look at the impeller: Some Mercury impellers look similar but are taller than the Force impeller. If you were given one of these by "misteak" and installed it, It would be so tight that it would completely bind the shaft. So, that is one thing to look at. When you put a Force impeller into the pump housing, if you put a straight edge on top, it would protrude no more than Oh, say--1/32 of an inch. If it is like 1/8 inch taller than the pump housing, then it is the wrong impeller.
