ISO backup prop Honda 110

W

Wood Zeppelin

New member
Hi Folks,

I'm looking for a backup prop for a new Honda 110. Since it's intended purpose is only to get me home in an emergency, would love to pick up any used ones that may be available? Where might a look for a use one?
 
I usually had a Stainless Steel as my primary prop, and a back up of Aluminum. The aluminum for a 22 with a 100 hp would be 13 x 15 (For Honda). Unless you have an exceptionally heavy boat, I would stick with 3 blade props.
 
Thanks for the info guys!

Yes, I have a 13.5" x 15 prop. With just me on a 22' Angler, I can get up to 6200 RPM (the range is 5500-6300, with 5900 recommended as optimum).

However, I am planning a family boat camping and fishing trip (FOUR adults + gear). Also, I may got to places like Lake Powell (~3500' elevation) but probably not higher than that.

My thinking is that a 14 pitch backup prop would be a good option. This could give the "lower gearing"I might want with bigger loads or higher elevations. However, when I look at genuine Honda parts, they skip from 15 pitch down to 13. But it seems other brands offer 14 pitch.

Should I just go with another brand that offers 14 pitch? Or does the jump to 13 pitch make more sense?
 
UPDATE:

The Honda west coast Master Tech just talked me out of a lower pitch. Instead he thinks I should go up to a 16 or 17 pitch.. why?

Because
(a) Newer fuel injected Honda's have barometers in them and the computer adjusts for elevation!

(b) Even with more load in a C-Dory, top speed is rarely a concern. I'll run a cruising RPMs more often (say 4000-4500?). At this RPM range, he argues, a 16 or 17 pitch would give me more speed and therefor lower fuel usage to go the same distance*.

*Note, this is considering my WOT RPM of 6200 (with just me in the boat) when 5900 is optimal and 5500 is the low end of the desired range.
 
Maybe I’m missing something on the new technology, but I think the computerized fuel injection, just automatically creates the optimal fuel to air ratio, which gives the best possible hp performance at varying altitudes. Without adding a turbo or other device for making up the oxygen loss of higher altitudes, there is still going to be hp loss, as altitude increases, so I think still need for reduced prop pitch even with computer/barometer fuel air adjustments.
 
Hunkydory":pg14259p said:
Maybe I’m missing something on the new technology, but I think the computerized fuel injection, just automatically creates the optimal fuel to air ratio, which gives the best possible hp performance at varying altitudes. Without adding a turbo or other device for making up the oxygen loss of higher altitudes, there is still going to be hp loss, as altitude increases, so I think still need for reduced prop pitch even with computer/barometer fuel air adjustments.
Click to expand...

My thoughts on this: (a) Air-fuel *ratio* is key to optimum combustion, efficiency and power. At higher elevation, the air density drops (less oxygen) and the ratio goes off. The computer can adjust this ratio back to optimum (less gas), otherwise it'd be running too rich (less power). I believe this would preserve your GPH or fuel usage. (b) But now there is less air AND less gas going into each cylinder, right? So I think that equates to less torque. Perhaps then it would require more RPMs to reach the same speed (?). So it seems the optimum ratio would get some of your power back, but not all.

Remember - prop change is like a gear ratio change in an axle. It doesn't magically produce "more power", but I think a lower pitch prop helps the engine to not lug at lower torque/power levels.

Conclusion: Lower prop pitch doesn't make more power. It just re-gears for less power. But Adjusting the air-fuel ratio *does* regain power. So maybe a prop change wouldn't be necessary until the elevation change was even greater(?)

Now this is my thinking, but I'm not an engine expert.
 
Boat engines lose about 3 percent of their horsepower for every 1,000 feet of elevation above sea level. The only way to get it back is to supercharge the engine. I lose 24 percent of my horse power at Yellowstone and about 12 percent at lake Powell. You would adjust your pitch down to get the engine to run at WOT. I run a 19 pitch at sea level and might have to go down to a 15 pitch at 8000 feet depending on how much weight is on the boat.
 
I have a Solas 4 blade prop that I ran on our Honda BF90A on our 22 cruiser.
SOLAS 1413-128-17 Aluminum 4-Blade Propeller - RH, 12.75" Diameter x 17" Pitch

It ran very nicely on our 22. Could be a good spare. We repowered with Yamaha and no longer need it. Located in Sequim.
 
drbridge":2yk6afdt said:
I have a Solas 4 blade prop that I ran on our Honda BF90A on our 22 cruiser.
SOLAS 1413-128-17 Aluminum 4-Blade Propeller - RH, 12.75" Diameter x 17" Pitch

It ran very nicely on our 22. Could be a good spare. We repowered with Yamaha and no longer need it. Located in Sequim.
Click to expand...

PM sent.
 
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