Check the rubber primer bulb to see if it is hard to the grip. If it is, have a marine mechanic check it over. It could be that the fuel line assembly is bad and needs to be replaced. Check the fuel tank for sufficient fuel. Inspect all the fuel lines and connections for any cracks or leaks. Ensure that the lines are fully connected between the fuel tank and the engine.
Check the inside of the outboard engine cover for oil residue. If you notice oil, this could mean that the rings are bad and may need to be replaced. Have a qualified marine mechanic investigate this problem for you.
Clean the spark plugs with a sandblaster if you notice oil on them. Usually, if the spark plugs have a gray hue to them, they should be fine. If not, replace them.
Check the seal (gasket, 1/8-inch thick) between the power-head and the fuel pump for any damage or wear and tear. Replace the gasket, if necessary. If the gasket is damaged, it could cause a leak in the system and the fuel pump will not work correctly.
Use a plastic bottle to squirt a small amount of oil and fuel mix directly into the carburetor air intake if the engine will not start, even after priming the fuel bulb. Pull the starter rope at the same time.
Ensure that the cover to the fuel pump is not cracked. Have it replaced, if necessary. A cracked fuel pump cover could affect the vacuum when priming the rubber bulb.
Turn the engine off and remove the pump screw to see if the pump is bad. Squeeze the primer and check if there are any fuel leaks coming from the vacuum hole on the rear of the pump. If you notice any leakage, it may mean that the diaphragm has malfunctioned. Have a marine mechanic investigate this for you.
Check for adequate pressure in the motor. Remove the spark plug and attach the compression test gauge. The correct reading should be between 60 PSI (Pounds Per Square Inch) and 90 PSI. If the reading is off, have a mechanic check out the system for you.
