Re: Mercury 500 No Start??
Fortunately, like all engines, you only need three things to get it to fire, Fuel, Compression and Ignition. To get it to run well you will need some sacrificial chickens, a mushroom from the tip of Kilimanjaro, an eye of newt and a voodoo doll of your favorite mechanic.
To check the spark; pull plug, attach plug wire, hold threaded portion against engine block, crank motor, look for spark.
To check compression; You will need a compression gauge. This tool is available at most automotive parts stores. Remove all spark plugs, thread tool into each of the spark plug holes, crank motor and record maximum pressure reading.
To check for fuel; This gets to be a pain in the butt, Is there fresh fuel in the tank? Is the primer bulb pumped up? Do you know the condition of the carburetors? Are they gummed up? Remove the cover for the main jet, is there fuel in there?......... Whatever you do, DO NOT USE STARTING FLUID! There is no lubrication in this stuff and it?s too hot for an outboard.
Good luck and after you get it running, BBQ the chickens and have some friends over to celebrate your accomplishment.