Recently purchased First 42 needs prop replaced. Hurth gearbox has no markings showing gear box reduction ratio or modle number. Boat has deep keel and tall rigging, Perkins 50 hp that seems to be the fast 4000 rpm engin. Need to know gear box ratio. Any thoughts? Thanks.
Specs for prop replacement f/First 42?
- Thread starter Greg Gladden
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prop
Greg; I have a '94 Bene 40 with the 50hp Perkins. It tops out at about 2300 RPM, well short of 4k. Are you sure your tach is right? 4k is pretty fast for a diesel. My prop is a 19 in. MaxProp, set to 23 degrees.
Greg; I have a '94 Bene 40 with the 50hp Perkins. It tops out at about 2300 RPM, well short of 4k. Are you sure your tach is right? 4k is pretty fast for a diesel. My prop is a 19 in. MaxProp, set to 23 degrees.
My 390 Oceanis
Tula has a Maxprop. Without tide and wind she motors at 6 knots at 1800rpm. She seems to rev lower than many other boats. 4000rpm would be very scary and smoke out the world. Unlike Larry I do not know the size or pitch setting.
Tula has a Maxprop. Without tide and wind she motors at 6 knots at 1800rpm. She seems to rev lower than many other boats. 4000rpm would be very scary and smoke out the world. Unlike Larry I do not know the size or pitch setting.
First 42 prop
Have an '84 First 42. Mine has same rig & keel config as yours, Perkins 50 and Hurth tranny with 2:1 reduc. Had a Gori two blade folder on for several years with good results. Put on a Australian SS Slipsteam two blade folder two seasons ago and had a serious problem this season: the poly cushion disintegrated and jammed the blade gearing in a partially opened position, a situation I did not discover until boat was hauled. My choice for the best prop would now be either the Gori THREE blade folder or Maxprop folder if you budget allowed. I am now corresponding with Seahawk PTY in Australia seeking resolution of what I deem a bad design.
Have an '84 First 42. Mine has same rig & keel config as yours, Perkins 50 and Hurth tranny with 2:1 reduc. Had a Gori two blade folder on for several years with good results. Put on a Australian SS Slipsteam two blade folder two seasons ago and had a serious problem this season: the poly cushion disintegrated and jammed the blade gearing in a partially opened position, a situation I did not discover until boat was hauled. My choice for the best prop would now be either the Gori THREE blade folder or Maxprop folder if you budget allowed. I am now corresponding with Seahawk PTY in Australia seeking resolution of what I deem a bad design.
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