Just talked to the service manager at Shields and they will let someone try a prop if they have it in stock and it's within factory recommendations for the engine/boat.
Per the Evinrude specifications, that engine should turn between 5000-5500 rpm at WOT. In ideal conditions, a properly-propped engine will run into the upper half of that range to maximize torque and efficiency. Speed is not necessarily a determining factor for the correct prop. There are many others to consider for optimal performance, including load, hull design, aluminum versus stainless, hole shot vs. mid- and upper-range, fuel efficiency, etc.
It's not an exact science, but factory recommendations based on performance tests are a good way to start selecting the correct propeller. But how you use the boat, boat design and load all play a significant role and the only way to really fine-tune one is by sea trials.
Loaner Prop?
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Re: Loaner Prop?
silverking wrote:Just talked to the service manager at Shields and they will let someone try a prop if they have it in stock and it's within factory recommendations for the engine/boat.
Per the Evinrude specifications, that engine should turn between 5000-5500 rpm at WOT. In ideal conditions, a properly-propped engine will run into the upper half of that range to maximize torque and efficiency. Speed is not necessarily a determining factor for the correct prop. There are many others to consider for optimal performance, including load, hull design, aluminum versus stainless, hole shot vs. mid- and upper-range, fuel efficiency, etc.
It's not an exact science, but factory recommendations based on performance tests are a good way to start selecting the correct propeller. But how you use the boat, boat design and load all play a significant role and the only way to really fine-tune one is by sea trials.
Well said!
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Re: Loaner Prop?
Thanks Demon.
I've tested fishing boats professionally for several national magazines over the last 20 years and have written often about propellers, hull design, etc.
I went through the same situation as Bofus when I bought my custom skiff and finally sent the third prop off to have it cupped and tweaked by computer diagnostics to achieve the right hole shot and bow lift. I'm on my third Evinrude, by the way, the last two E-TEC 200s.
I've tested fishing boats professionally for several national magazines over the last 20 years and have written often about propellers, hull design, etc.
I went through the same situation as Bofus when I bought my custom skiff and finally sent the third prop off to have it cupped and tweaked by computer diagnostics to achieve the right hole shot and bow lift. I'm on my third Evinrude, by the way, the last two E-TEC 200s.
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Re: Loaner Prop?
Tried to test a used prop at Mike's Marine today and was told I needed to pay in full for it and then had a one hour limit to test it if I wanted the option to return it. My response was I didn't mind paying but a one hour test window wasn't going to work....not that it couldn't be done, just seemed unnecessarily PRICK'ly considering it contradicted what I was told on the phone.
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Re: Loaner Prop?
Mike's Marine is GOOD folks....hate you got your wires crossed