my '04 F50 is getting harder and harder to start when cold.I've drained the carbs and emptied the water seperator more times than I can count.It takes about 6 tries before it gets warm enough to run.It burps through the airbox a few times before it will stay lit it.Once firing she'll run pretty smooth.I know the gas we get here is cut with ethanol which attracts water.I'm wondering if the prime system is starting to fail me.Is there a way to test the primer system to be sure it's functioning?If I cover up the airbox and try starting it when cold will that give a richer fuel mixture? I hope to get out next weekend but I'm losing confidence in this engine.
To test the prime start valve; remove the valve an connect up 12 v; blue lead to positive black lead to negative -leave connected for 5min, check the heater element for any hieght increase, the increase should be min 14.6mm.
I suggest you tear down your carb, clean and use compressed air. The sinc needs to be done using a techmate manometer or a suitable vacuum gauge.