63 mercury 650 needs more speed-power

[dennis1980]

i have a 73 ski boat and a 63 mercury 65hp top speed is 26mph this is my first boat and i was wondering if that is slow it seems like it to me and is it the prop and would those fins make the difference if its the prop what should i switch to and is it ok to get the fins from farm and fleet

 

[Yepblaze]

Re: 63 mercury 650 needs more speed-power

That sounds a bit slow. Perhaps your best place to start is by doing or having done a set of diagnostic procedures.<br /><br />By disabling one cylinder's spark at a time it might be possable to note one or more cylinder not running, or running as well as the rest of them. <br /><br />Followed by a compression check.<br /><br />If those test checked out OK I'd start looking towards the fuel system. Perhaps fuel pump and carb diassembling,cleaning, and reassembly with new gaskets and such.<br /><br />It is possable that someone has chosen the wrong propeller sizing for your particular motor but unlikely.