Aeolus
Well-Known Member
Happy New Year one and all!
I replaced my Volvo Penta MD7a (13 HP, approx 170kg) with a Beta 20hp weighing 105kg. The new propellor is slightly smaller: 14x9 2 blade instead of a 15x9 2 blade. Prop shaft length and angle are the same as before. Engine is towards the stern, under the companion way steps.
When motoring, the boat (30' Seamaster 925 sailing boat, long fin) always used to sit a bit lower in the water at the stern but now, with the new engine, it sits much lower so that the exhaust outlet which faces downwards, just under the transom, is often in the water.
Since the boat has less weight in the stern, I expected the opposite to happen. Any ideas why the boat tilts backwards more than before and what I can do about it?
Does it matter that the exhaust is in the water when motoring? At rest, the exhaust outlet is clear of the water and I've got an anti-syphon / water trap thingy to prevent water going up the exhaust.
I replaced my Volvo Penta MD7a (13 HP, approx 170kg) with a Beta 20hp weighing 105kg. The new propellor is slightly smaller: 14x9 2 blade instead of a 15x9 2 blade. Prop shaft length and angle are the same as before. Engine is towards the stern, under the companion way steps.
When motoring, the boat (30' Seamaster 925 sailing boat, long fin) always used to sit a bit lower in the water at the stern but now, with the new engine, it sits much lower so that the exhaust outlet which faces downwards, just under the transom, is often in the water.
Since the boat has less weight in the stern, I expected the opposite to happen. Any ideas why the boat tilts backwards more than before and what I can do about it?
Does it matter that the exhaust is in the water when motoring? At rest, the exhaust outlet is clear of the water and I've got an anti-syphon / water trap thingy to prevent water going up the exhaust.
