Bought a used Tracker with a 75hp Merc on it a couple of years ago.
It's always had some issues with hard starting, and wanting to die while trolling on occasion.
Pump the bulb and it would fire right back up. Ran fine at any speed other than idle, although 4600 was all the rpm the engine could muster.
Started getting worse, so started researching the internet and got a combo of a vacuum leak and/or fuel pump.
Went to the local boat dealer and got a $185 dollar price on a fuel pump. He mumbled something about there used to be a kit, but it was discontinued.
After deciding to do some more research got online and found the diaphragm and check valve kits are readily available for $28.00.
Quite a difference in price. Took about an hour to separate the pump, rebuild it and put it back on. Do it in half the time now since I know what's going on.
Gained 600 rpm and 7 mph after the rebuild.

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