Re: how much pressure?
Benja,<br /> According to the Clymer manaual, you should have 2-5 PSI @ 2000 RPM @ the cylinder block. I think they make a gauge to plug into the water jacket to check. I had a weak stream on my 74 150 and had to insert a coat hanger into the tell tale and remove some sediment and then noticed a much steadier stream. I think I can also plug it with my finger as well. Others on the board really recommend a standard impeller replacement if you have just bought the boat or it has sat up for a long time--just to be safe. Re: speed at WOT, read my thread (performance question). I'm, in the same situation trying to figure out what will work best. I'm getting 36 MPH @ 5400 RPM on an 18 ft. Glastron with a 15 pitch--but others definitely think I can get more out of it. Let me know what you find out or learn from experimentation. It will help me and others I'm sure.
