"I have new twin Yamaha 150 fo
"I have new twin Yamaha 150 four strokes with less than 40 hrs and both make a constant low clattering noise from the lower unit/gearcase when I run them in idle forward gear with flushing muffs and a garden hose. I don't hear any noise when the engines are in neutral. Both gearcase lubes have been inspected and changed, and the fluid was clean. My dealer says this is normal, that the props need the resistance of the water to take the up the gear slack. He may be right, because I don't hear this noise when the engines are run in idle forward in the water. So is this really normal, or am I getting bad info from the dealer and need to pursue this further?"
"I have new twin Yamaha 150 four strokes with less than 40 hrs and both make a constant low clattering noise from the lower unit/gearcase when I run them in idle forward gear with flushing muffs and a garden hose. I don't hear any noise when the engines are in neutral. Both gearcase lubes have been inspected and changed, and the fluid was clean. My dealer says this is normal, that the props need the resistance of the water to take the up the gear slack. He may be right, because I don't hear this noise when the engines are run in idle forward in the water. So is this really normal, or am I getting bad info from the dealer and need to pursue this further?"