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#1
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I just re-proped my boat -- my range is supposed to be 4200-4600
is this under "best case" conditions? (flat water, no wind, light load, trim optimised, etc) Or "no mater what, when you're "WOT" your engine should be between 4200-4600? Thanks Davie |
#2
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![]() "Dave Jones" wrote in message ... I just re-proped my boat -- my range is supposed to be 4200-4600 is this under "best case" conditions? (flat water, no wind, light load, trim optimised, etc) Or "no mater what, when you're "WOT" your engine should be between 4200-4600? Thanks Davie It should be optimized for your normal loading and usage and depends a lot on the size of your boat. That RPM range indicates a likely I/O setup and I assume it's a single engine. You may find out, as I did years ago, that you will have two props ... one for normal use with 2 or 3 people aboard and a second, lower pitched prop for when the whole gang shows up for a boat ride. RCE www.eisboch.com |
#3
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That's why it's a range..... 4600 lean and mean 4200 with the whole fam
damily. But assume 4600 is max at leanest config, so if you prop it lighter, watch the tach and don't exceed. -W "Dave Jones" wrote in message ... I just re-proped my boat -- my range is supposed to be 4200-4600 is this under "best case" conditions? (flat water, no wind, light load, trim optimised, etc) Or "no mater what, when you're "WOT" your engine should be between 4200-4600? Thanks Davie |
#4
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Someone should invent an easily adjustable, variable-pitch prop. Maybe
I will. I just hate pulling the prop off my OMC. Jeff Dave Jones wrote: I just re-proped my boat -- my range is supposed to be 4200-4600 is this under "best case" conditions? (flat water, no wind, light load, trim optimised, etc) Or "no mater what, when you're "WOT" your engine should be between 4200-4600? Thanks Davie |
#5
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posted to rec.boats
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![]() "Chehalis Jeff" wrote in message ps.com... Someone should invent an easily adjustable, variable-pitch prop. Maybe I will. I just hate pulling the prop off my OMC. Jeff I think one of the outboard manufacturers (Mercury?) tried to introduce an "automatic" variable pitch prop many years ago that had two pitch positions. It was costly, problem prone and it's performance wasn't any better than a properly sized fixed pitch prop. The prop was a flop. RCE www.eisboch.com |
#6
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posted to rec.boats
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RCE wrote:
"Dave Jones" wrote in message ... I just re-proped my boat -- my range is supposed to be 4200-4600 is this under "best case" conditions? (flat water, no wind, light load, trim optimised, etc) Or "no mater what, when you're "WOT" your engine should be between 4200-4600? Thanks Davie It should be optimized for your normal loading and usage and depends a lot on the size of your boat. That RPM range indicates a likely I/O setup and I assume it's a single engine. You may find out, as I did years ago, that you will have two props ... one for normal use with 2 or 3 people aboard and a second, lower pitched prop for when the whole gang shows up for a boat ride. RCE www.eisboch.com Excellent advice. For my Evinrude 115(16' Glastron), I have a SS 19" prop that is good for overall use, a SS 17" prop for heavy loads w/ watersports & gear for a day away from the dock, and a large surface area AL 15" prop for power on demand (we sometimes pull 5 skiers with this prop) but even with 5 skiers in tow, the engine will over-rev at full throttle once they are up. Our old inboard is getting tired, I have 2 14", a 15", a 10" & a 9" NiBrAl (or brass) props for it, it likes the 14" cupped Michigan the best at 4600-4800 rpm(engine is rated 220hp at 4400) . It over revs with the 14" Stannus, to almost 5000 rpm, this we do only for short bursts with a good load in the boat. I/O & inboard engines(& most outboards - some Mercs are VERY sensitive to this) really should not be run for any duration over recommended WOT max. Target the middle of the range with your usual load. Rob |
#7
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I just put a 21" pitch on my boat (same range) and WHAT A DIFFERENCE! 10mph
improvement and still w/in range (supposed to use a 19) That was iwth me - tonight I'll take my wife to work (two people) and bring friends back (5 people total). We'll see how it runs then. As I understand it; the WOT rpm range is under "ideal" situations. On Thu, 15 Jun 2006 13:11:43 -0700, Dave Jones wrote: I just re-proped my boat -- my range is supposed to be 4200-4600 is this under "best case" conditions? (flat water, no wind, light load, trim optimised, etc) Or "no mater what, when you're "WOT" your engine should be between 4200-4600? Thanks Davie --- AntiSpam/harvest --- Remove X's to send email to me. |
#8
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posted to rec.boats
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That's why it's a range..... 4600 lean and mean 4200 with the whole fam
damily. But assume 4600 is max at leanest config, so if you prop it lighter, watch the tach and don't exceed. So my new 21" pitch -- me alone, WOT , semi-flat water trimed right, 4300 RPM -- the prop is no good? Too much strain on the engine? (I may have 14.5x21" prop for sale soon) --- AntiSpam/harvest --- Remove X's to send email to me. |
#9
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posted to rec.boats
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![]() "RCE" wrote in message ... "Dave Jones" wrote in message ... I just re-proped my boat -- my range is supposed to be 4200-4600 is this under "best case" conditions? (flat water, no wind, light load, trim optimised, etc) Or "no mater what, when you're "WOT" your engine should be between 4200-4600? Thanks Davie It should be optimized for your normal loading and usage and depends a lot on the size of your boat. That RPM range indicates a likely I/O setup and I assume it's a single engine. You may find out, as I did years ago, that you will have two props ... one for normal use with 2 or 3 people aboard and a second, lower pitched prop for when the whole gang shows up for a boat ride. RCE www.eisboch.com Are you telling us that you actually changed props each time your guest list changed? |
#10
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Josh Assing wrote:
That's why it's a range..... 4600 lean and mean 4200 with the whole fam damily. But assume 4600 is max at leanest config, so if you prop it lighter, watch the tach and don't exceed. So my new 21" pitch -- me alone, WOT , semi-flat water trimed right, 4300 RPM -- the prop is no good? Too much strain on the engine? Looks good from here... Rob (I may have 14.5x21" prop for sale soon) --- AntiSpam/harvest --- Remove X's to send email to me. |
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