- The Hull Truth

r.waddill · 06-19-2002, 10:44 AM

As I am gearing up for my trip to the Abacos i have a pprop question for the experts here. Currently I run a 3 blade stainless prop on a single 250hp yamaha on a 25 Bluewater. I believe I am turning about 5200-5400 WOT . I would like to replace the stainless with a new 4 blade aluminium and use the stainless as a spare on the trip....What kind of performance could I expect and what size should I look for? Has anyone used the aluminum 4 blades i think they are new...someone told me i could get them at West marine

Mako Madness · 06-19-2002, 12:58 PM

R, I run a 250 on my 25. Just put a 4 blade on but have not run it yet. I'll let you know. The guys at Frank &Jimmy's prop shop said i shoul get better mid range. Which is what i am looking for for the same reason , running to the Bahamas.
What size are you running. I had a 14.5 x 17 3 blade and put a 14.5 x 17 revolution 4.

Mako Madness
www.sfmoc.org

kennethk · 06-20-2002, 05:07 AM

Check out www.propcopropellers.com
Bass pro also sells them
They have 3 and 4 blade aluminum

Got one for my Honda 130, good stern lift, gets on plan at a lower speed, lower top end speed, higher fuel consumption

Ken

r.waddill · 06-20-2002, 05:45 AM

Mako,
I am not sure what size prop it is. I do know I have never seen a stainless prop that looks like this one. It almost looks as if the tips of the prop has been cut with a pare of tin snips. I am very curious to know what size I have on it. I am going to call Paul at Bluewater to find out what size they ordered with the motor. i am anxious to here about your findings with your 4 blade. Keep me posted.

Mako Madness · 06-20-2002, 07:16 AM

I should have her out within the week. A few touchups on the bottom paint and ready to go.

Mako Madness
www.sfmoc.org

Fishywaters · 06-20-2002, 10:54 AM

R.Wadill- I have he same prop on my 200 Ocean Runner. Paul put the boat package together in 98, 2350 Bluewater. I'm not sure how to check the size and pitch but also need a spare onboard. I'll stay tuned to see what other responses you get.

Stockbroker · 06-20-2002, 12:06 PM

Maybe I am missing the boat (pardon the pun) but why would you go to an aluminum prop for such a high HP engine? Aluminum props flex under high torque situations thus you find them mostly on smaller engines. Is this a special prop or is there something that makes this a better prop for your boat? Just curious....oh and by the way, you do deserve a commission with Paul on my 2850. Thanks again, it rides great.

SB

Mako Madness · 06-23-2002, 07:54 PM

Ok got the boat back in the water and couldn't wait to get in an area I could get on plane. Initially it had awsome hole shot and noticably better lift. Better mid range in the RPM. Then I decided to take it to WOT. I got it to 5200RPM and 38 mph for about 10 secs and it spun the hub. A brand new hub I might add. SO the 250 is way too much HP for that load. I think a 13-1/2" x 17 would be the way to go by reducing the size of the prop and therefore the load on the hub.

http://www.propcopropellers.com/yamaha.htm

this web site indicates what is most likley the correct prop for your boat. It states
3 blade 14.5 x 17 What I have
4 blade 14.5 x 17 What I tried
4 blade 13.5 x 17 What it should be

this make sense and I would follow it.
I on the other hand will not be buying a 4 blade prop as it's not worth $400 to get a bit better economy. The 4 blade I have was given to me so I felt it worth a try.

Mako Madness
www.sfmoc.org

Mako Madness · 06-24-2002, 12:35 PM

Ok I spoke to Frank & Jimmie's Prop Shop and they said they would take a look at the hub and recommend something. They make hubs that are stronger so lets see.

Mako Madness
www.sfmoc.org

Capt Phil · 06-24-2002, 01:39 PM

I've got a 25' parker with a Yam 250 and a 17 pitch prop. It seams like the perfect combo.

I'd be real curious what, if any cruising advantage you get from the 4 blade prop.

I'm thinking about changing to a new YAM 4stroke 225 for this boat. Do you think I would still be able to turn a 17 pitch ??

PP

Mako Madness · 06-24-2002, 02:05 PM

my 3 blade 17 is perfect. i was trying a 4 blade to compare.

Mako Madness
www.sfmoc.org

kennethk · 06-24-2002, 04:38 PM

I'm not an expert but I'm playing around with a prop for my 130 Honda on my 185 Scout. Below are some basic numbers. Tomorrow I will get the 13 x 17 4B back from Propco modified to a 12 1/2 x 17 in hopes to get the RPM up.
Propco says for every 1/8" less in diameter you gain 100 RPM

13 1/2" x 17 3B SS Ballistic
RPM Speed MPG
2000 7.2 3.6
3000 12.0 3.4
4000 26.3 4.9
5000 35.3 4.3
5700 41.9 3.3 Max

13 x 17 4B Alum Propco
2000 7.0 3.3
3000 17.5 5.1
4000 27.7 4.4
5000 35.0 3.2
5200 38.0 3.0 Max

13 x 21 4B Propco
3000 20.0 5.0
4000 31.0 4.4
4700 38.6 3.5 Max

Ken

Mako Madness · 06-24-2002, 06:19 PM

OK Update. I spoke with my neighbor and he said I may have hit a underwater dredge line. He told me his kid hit it in his skiff around the same location. They must have moved it because it was running down the side of the canal the last time I went by.

Heading over to get a new hub tomorrow and try again however I will run on the opposite side of the the dredgeing barge and have a better idea of the performance. The guys at the prop shop sounded supprised that the hub spun just bu driving so this seems like the plausible cause. If that is what happened then the hub worked flawlessly by protecting the engine.

Mako Madness
www.sfmoc.org

Mako Madness · 07-01-2002, 10:36 AM

Ok was able to do a 25 mile run offshore Sunday. The 4 blade performed great and we were able to get better midrange and hole shot. I don't boat as much as I would like sice the baby was born so for me the investment would be questionable at this time. If you boat every week then I would say go for it.

Mako Madness
www.sfmoc.org