merc 9.8 serial #

My Serial # is 7151121 Canadian I think, and supposed to be a '81. Where can I find info on this motor to confirm the year?<br />Also need advice on cleaning the carb and installing a new fuel pump kit. It also idles a little fast for trolling so I would like to slow it down short of installing a smaller prop.<br />Thanks for your help.

Re: merc 9.8 serial #

You're correct it is a 1980/1981. Merc used the same serial number range through both years and it is impossible to distinguish between them.<br /><br />The best approach is to buy a manual for that motor. An aftermarket will do, but the factory manual is best. Mercury p/n 90-86136--1<br /><br />Carb cleaner, a gasket kit, a new needle/seat and you should be all set. Inspect your float for leaks. It needs to be air tight and float, obviously. The fuel pump kits typically comes with the check valves and gaskets.<br /><br />You should see a number stamped in the carb to distinguish which type you have. Either one should have the side mount fuel pump.<br /><br />Idle speed can be adjusted, by turning the idle speed screw. Ideally somewhere between 600 to 800 rpm in the water. You may find that a smaller prop is the only option to slow down for trolling, unless you opt for a trolling plate or dragging a pail to slow you down.<br /><br />Check out dougrussel.com, or mercruiserparts.com for exploded parts diagrams. iboats may sell the parts you need, or a quick visit to a local Merc dealer will suffice.

Re: merc 9.8 serial #

Thanks for your help, will try that. We are 50 miles from a dealer so I wanted to make sure before going out.