I'm looking for the 'right' prop. for a Seidelmann 25. Someone put a left-handed prop on & it just isn't working! Can anybody tell me the right pitch & diameter?
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Peter, There should be a plate on the transmission
that gives the gear ratio. Generally 2 inches of clearance between the prop and the hull is recommended. Take your prop to a propeller shop and tell them what you are dealing with. I had mine repitched and reconditioned this spring for $125. That will be your least costly effort. A good prop man can be a big help.
that gives the gear ratio. Generally 2 inches of clearance between the prop and the hull is recommended. Take your prop to a propeller shop and tell them what you are dealing with. I had mine repitched and reconditioned this spring for $125. That will be your least costly effort. A good prop man can be a big help.
Left-handed-monkey-wrench!
Peter, Most props are right hand, meaning looking from aft towards the bow it will turn to the right, ie 'Clockwise'. Leftys turn counter-clockwise and if you did have a 'right-hand' in place of a left, it does work, but you would be in reverse to go forward; your shifter would likely be pulled back for forward as opposed to forward as normal. Don't mess around with this, take your prop, manual and all stats, especially your LWL "length at the waterline" in to a real prop shop, pitchometer, or somewhere that uses their computer to get the perfect matched prop for your vessel. This is not for any home-spun magic or wives tales here, do this right once and for all.
Peter, Most props are right hand, meaning looking from aft towards the bow it will turn to the right, ie 'Clockwise'. Leftys turn counter-clockwise and if you did have a 'right-hand' in place of a left, it does work, but you would be in reverse to go forward; your shifter would likely be pulled back for forward as opposed to forward as normal. Don't mess around with this, take your prop, manual and all stats, especially your LWL "length at the waterline" in to a real prop shop, pitchometer, or somewhere that uses their computer to get the perfect matched prop for your vessel. This is not for any home-spun magic or wives tales here, do this right once and for all.
I can see where this can turn into an advise
match. There are many transmission types and many propeller types. My Volvo transmission doesn't care if it turns a left or right hand prop I just have to move the control cable to a different position. The forward and reverse ratios are the same. BoatDiesel.com has a calculator available to members. Given your boat displacement, engine hp, cruising rpm, max rpm, and gear ratio they recommend a proper prop. Constraints here being clearance.
match. There are many transmission types and many propeller types. My Volvo transmission doesn't care if it turns a left or right hand prop I just have to move the control cable to a different position. The forward and reverse ratios are the same. BoatDiesel.com has a calculator available to members. Given your boat displacement, engine hp, cruising rpm, max rpm, and gear ratio they recommend a proper prop. Constraints here being clearance.
Right prop
Peter, Have you operated the old girl with a clean prop? You can not judge her with a prop as fouled as the picture indicates. It is amazing she moves at all. I had a Honda 7.5 horse outboard on my S25 and she moved along very well, but I could not tell you what the dia and pitch was. By the picture I would say the diameter is fine, so what you need is the pitch which depending on the gear ratio I would expect to be 8 to 10 inches. Skipper Sailing vessel Promises
Peter, Have you operated the old girl with a clean prop? You can not judge her with a prop as fouled as the picture indicates. It is amazing she moves at all. I had a Honda 7.5 horse outboard on my S25 and she moved along very well, but I could not tell you what the dia and pitch was. By the picture I would say the diameter is fine, so what you need is the pitch which depending on the gear ratio I would expect to be 8 to 10 inches. Skipper Sailing vessel Promises
More Prop!
We got the left-handed prop cleaned up and it is labeled as 11x8. When I'd swum down & cleaned a long, long time ago, we did get some propulsion out of it. With the growth pictured, we got no propulsion at all. Can't wait. We just have to get an better , RH prop, patch up the bottom & the rudder repaired & back into the water! The rudder may be an adventure. I'm hoping there isn't too much water or corrosion in there.
We got the left-handed prop cleaned up and it is labeled as 11x8. When I'd swum down & cleaned a long, long time ago, we did get some propulsion out of it. With the growth pictured, we got no propulsion at all. Can't wait. We just have to get an better , RH prop, patch up the bottom & the rudder repaired & back into the water! The rudder may be an adventure. I'm hoping there isn't too much water or corrosion in there.
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