engine new to me,previous history stated to be good. Engine will start, runs rough from idle to higher rpm. Rough under load. 1850 hrs. total time, saltwater use. complete new fuel system, tank to carbs. carbs completely disassembled, cleaned, set to Yamaha spec. New NGK BR8U plugs. compression good 115 - 120. Spark at all coils. Reed valves appear to be good, all the same. When engine is running, it seems like cyl. 1-4 are dropping out and lower carb is the only one senstive to restricting air with you hand.
Anyone have similar experience or suggestion on where to look next? This engine is on a 23 Whaler with twin identical engines( L/H & R/H rot.). so I'm about to start swapping parts, to identify any change.
Anyone have similar experience or suggestion on where to look next? This engine is on a 23 Whaler with twin identical engines( L/H & R/H rot.). so I'm about to start swapping parts, to identify any change.