Yesterday I bought a used 7.5 Merc for the 12' jonboat(GF12 from bateau.com)that I have under construction in my backyard. It was in excellent shape and the price was right so I had to get it without much "due diligence". It is the long shaft model, serial #5228622, which I believe is a 1979 model.<br /><br />Now the questions:<br />1. The motor is 22" from transom clamp to cav plate. Was this the standard long shaft for the older motors? Newer motors seem to be 20" for the long shaft versions.<br /><br />2. The 3 bladed prop seems to have a noticibly flat pitch. I am now thinking that this maybe is a "high thrust" prop made for heavy boats. The previous owner used the motor as a troller on his 20" fishing boat and said it was the "standard" prop. How can I check the prop pitch? If I have to change props, who would be a good source for a replacement. These older props seem to be hard to find.<br /><br />3. I will be fishing/using the boat at lake elevations from 2000' to 6000'. What prop and carb jet issues should I anticipate at these altitudes? This was much easier when I lived in Fla., everything was at sea level!
