FS14 -The Ana Marie

[Fuzz]

I bet 25 mph in a 14 foot boat feels like you are flying.

[OrangeQuest]

I bet 25 mph in a 14 foot boat feels like you are flying.

On a smooth lake it isn't so bad. 1-1.5 foot chop and it can be very exciting. Maybe if I was younger, I wouldn't stress so much but I like 17-18 mph in the rough conditions and sometimes even slower. I am trying to ease into learning her limits and mine. She seems to have higher limits than me, which I think that is a good thing.

Funny thing, some may relate. I was rinsing the cockpit out yesterday when I first got back from our adventure. The battery power was still on, so I could remove the transom saver and port flush the motor. I have been leaving the two bilge pumps on auto when the power is on. The 500gph pump just happened to kick in as I was standing on the port side of the boat. Was quickly wearing 500gph bilge water.

[TomW1]

Nice OQ! If you want I can calculate what your max speed and what prop you should have on her. I believe that 5500 rpm's is not the max for that motor most Suzuki's have a top rpm of 6-6300rpms.

Let me know what Suzuki you have HP, shaft length etc., year and I will work up some numbers for you. I believe you are not reaching the full potential of your motor to your FS14. The other thing I will need is the weight of the boat as she leaves the dock. If you do not know the weight of the water give me the tank size, the same with fuel and I can calculate them.

Regards, Tom

[BarraMan]

I bet 25 mph in a 14 foot boat feels like you are flying.

Probably depends on the boat!
My “little” boat sits nicely on 23 kts (26 mph?) at WOT (40hp Yammie 4 stroke).

50 kts in a 22’ boat - now that DOES feel like you are flying!

[OrangeQuest]

Nice OQ! If you want I can calculate what your max speed and what prop you should have on her. I believe that 5500 rpm's is not the max for that motor most Suzuki's have a top rpm of 6-6300rpms.

Let me know what Suzuki you have HP, shaft length etc., year and I will work up some numbers for you. I believe you are not reaching the full potential of your motor to your FS14. The other thing I will need is the weight of the boat as she leaves the dock. If you do not know the weight of the water give me the tank size, the same with fuel and I can calculate them.

Regards, Tom

My owner's manual and shop manual both state that the operating rpms should be in the 5000-6000 range for a DF25A. If it were a 30HP then your numbers are correct. With the extra cloth I put inside and out on the hull, sole, 1 extra full size frame and one extra frame at only 3" across, I think my boat is a little heavier than a standard built FS14. Plans state the draft should be 5", mine is at 7"to 8"at the transom. That is the scum line left on the hull after running it for a few hours. Which when I was testing what the water line needed to be when I was measuring for the tank's pump, I needed a DWL at 7" or the pump would only suck air.

From the start I was commenting the boat would be built heavy and was warned the 25hp was a little much, but it seems the boat needs that hp to push it above 20mph at the weight she is at. But I never planned on having 2-45pound batteries. or a stereo for that matter. My guess, I could pull the 2 batteries out and the boat could easily top over 30mph with the prop it has. I have no need for that kind of speed and I like the way she is performing so far.

As far as props go, I would like to try a 4 bladed prop but the only prop I find close to what I already have (I think I need less pitch?) is a Solas Amita in a 10.2X11. How much would the slightly smaller dia help? Then a 3 blade at 11X9, same brand. Factory prop is 11-1/4 X 10. The 4 blade seems would only drop my rpms but the 3 blade may bring the RPMs up a little and give me better acceleration. I want a spare prop but the selections are very limited for a small HP outboard. And I think if I swap out props it will be less pitch/dia.

I bet 25 mph in a 14 foot boat feels like you are flying.

Probably depends on the boat!
My “little” boat sits nicely on 23 kts (26 mph?) at WOT (40hp Yammie 4 stroke).

50 kts in a 22’ boat - now that DOES feel like you are flying!

I think you are right BarraMan. A well trimmed and proper weight distribution of a boat will make it a more comfortable ride and more stable at higher speeds. Look at jet skis that do 60mph+ and they are a lot smaller than a 14 foot skiff.

[TomW1]

OrangeQuest you are right the DF25's operating range is listed at 5000-6000rpms. Also, per weight the PPI is 220 so at 7" draft your boat weighs around 1025lbs at Designed Displacement. Since you are only getting 5500 you are not getting max performance from your motor. When I prop a boat, I prop it to be within 200 rpms of max rpms. So, for now you need to go down in pitch 2", that will take you up to 5900-6000rpms. at max throttle. So, your 3-blade should be an 11 1/4 x 8 and extra rpms will give you the same top speed. Now for a 4-blade, PtProps has as an SRA 4-blade 10 x 8 https://www.ptprop.com/b-clabss-propellers1.html that should give you excellent lift, handling and rough water handling plus better straight-line steering. I always prefer a 4-blade if running in choppy water most of the time.

I am taking the designed displacement and draft from the study plans as well as the PPI.

If you have any questions, please ask.

Tom

[OrangeQuest]

OrangeQuest you are right the DF25's operating range is listed at 5000-6000rpms. Also, per weight the PPI is 220 so at 7" draft your boat weighs around 1025lbs at Designed Displacement. Since you are only getting 5500 you are not getting max performance from your motor. When I prop a boat, I prop it to be within 200 rpms of max rpms. So, for now you need to go down in pitch 2", that will take you up to 5900-6000rpms. at max throttle. So, your 3-blade should be an 11 1/4 x 8 and extra rpms will give you the same top speed. Now for a 4-blade, PtProps has as an SRA 4-blade 10 x 8 https://www.ptprop.com/b-clabss-propellers1.html that should give you excellent lift, handling and rough water handling plus better straight-line steering. I always prefer a 4-blade if running in choppy water most of the time.

I am taking the designed displacement and draft from the study plans as well as the PPI.

If you have any questions, please ask.

Tom

I think your estimate is close to right. I would need to find a set of scales to verify the weight any closer. THANK YOU FOR YOUR INSIGHTS.
I looked for the PT props and only think I see is $400 SS props and I want to stay away from stainless steel. When the boat cruises up our bayous the lower unit can make contact with a lot of hard things. I do want to get a prop that at WOT it just hits the rev-limit. Then when I need to haul a really heavy load I can prop to it.

Since my budget have become very tight, what are your thoughts on the 3 blade 11X9 and/or the 4 blade 10.2 X11. Even though the 4 blade pitch is 1 inch higher can the small diameter be enough to increase the rpms but get the benefits of a 4 blade? I can get them both for under $200 and free shipping.

[TomW1]

OrangeQuest you are right the DF25's operating range is listed at 5000-6000rpms. Also, per weight the PPI is 220 so at 7" draft your boat weighs around 1025lbs at Designed Displacement. Since you are only getting 5500 you are not getting max performance from your motor. When I prop a boat, I prop it to be within 200 rpms of max rpms. So, for now you need to go down in pitch 2", that will take you up to 5900-6000rpms. at max throttle. So, your 3-blade should be an 11 1/4 x 8 and extra rpms will give you the same top speed. Now for a 4-blade, PtProps has as an SRA 4-blade 10 x 8 https://www.ptprop.com/b-clabss-propellers1.html that should give you excellent lift, handling and rough water handling plus better straight-line steering. I always prefer a 4-blade if running in choppy water most of the time.

I am taking the designed displacement and draft from the study plans as well as the PPI.

If you have any questions, please ask.

Tom

I think your estimate is close to right. I would need to find a set of scales to verify the weight any closer. THANK YOU FOR YOUR INSIGHTS.
I looked for the PT props and only think I see is $400 SS props and I want to stay away from stainless steel. When the boat cruises up our bayous the lower unit can make contact with a lot of hard things. I do want to get a prop that at WOT it just hits the rev-limit. Then when I need to haul a really heavy load I can prop to it.

Since my budget have become very tight, what are your thoughts on the 3 blade 11X9 and/or the 4 blade 10.2 X11. Even though the 4 blade pitch is 1 inch higher can the small diameter be enough to increase the rpms but get the benefits of a 4 blade? I can get them both for under $200 and free shipping.

I will get back to you tomorrow, spent today at various appointments and feel wiped out. Tom

[TomW1]

Okay OrangeQuest lets get started again. You mention that you want to get a prop that just gets to the rev limiter, on the Suzuki's that is about 2000rpms above the stated operating range of 6000rpms. So now we are looking move the rpm range from 5500 to 6200 or 700rpms. So we have to reduce either the diameter or the pitch or both. So, looking at your factory prop of 11.25 x 10 we need to go down either in diameter or pitch. An inch in decrease in diameter is the same as reducing pitch by about 2.5 inches. A decrease in pitch increases rpms by about 200rpms per inch.

I have found a Michigan Match prop that should get you up close to 6000rpms. https://www.boatpropellerwarehouse.com/ ... ler-062208 Michigan Match are well known and have excellent reputations; you can read the reviews. It is a little more expensive but only about $40 or so, hopefully can fit your budget. Don't know if shipping is included by this vendor. You maybe can find one that does include it, or you have a dealer nearby.

As far as the 4-blade I am also having trouble finding one to fit your DF25A. The best I can find is a Michigan Vortex 11.5 x 8 which leaves your rpms about the same as you have. But you gain the advantages of the 4-blade. https://www.boatpropellerwarehouse.com/ ... ler-992401 The disadvantage I see is that buy the hub for your motor also.


Please ask if you have any questions.

Tom

[bklake]

Solas makes a 4 blade for the Suzuki. I didn't check the availability. They list 11" thru 15" and 10" diameter.

I have a Solas 4 blade on my Suzuki V-Twin 25HP. No problems with the prop.