I have a Beta 20BHP 3 cylinder which is exhibiting difficult starting after the first initial 1 or 2 starts, it will fire but needs throttle massage to get going on the 3rd try.
Have done: New OEM filters with correct air bleed out, tightened ALL connections on 'suction' side of the fuel system as well as the return line, (even the gland nut on the ball valve at the tank, every (!) connection), NO signs of water contamination or sediment. High quality fuel purchased from a reputable supplier, no bio diesel. When running no loss of power, only hard start issue.
Checked the power to the glow plugs and ok, (9.5vDC) will find out the resistance of the glow plugs soon (and or comment if you know it) and test them, but I don't think this is the problem.
The engine will start fine from an overnight 'cooling' (Bay Area San Francisco Ca for general temps), warm up, put in gear for 10 minutes on mooring lines, shut down, wait 15 minutes, starts right up, wait 30 min again...HARD STARTING.
Sadly, there is no hour meter on this boat and the owner doesn't have a feel for running hours...Ideas?
Valve adjustment I think is next but I can't see this as a direct correlation, but I'm all ears.