prop ? Gulfstream with a F225

[Pfeehley]

Hey all, I want to hear from you past/present guys with gulfstreams with single Yamaha F225s. I’m running a 14 1/4x17 ss prop and I’m cruising at 5500 rpms 27-29 mph. Not really fast to get on plane and having a hard time staying there under 5k. Best top end I’ve seen is 34.xx mph @6100 rpm. I’m not looking for a speed machine but a little faster plane and sub 5k cruising would be ideal.

I’ve seen some guys say they cruise in the mid 4K range and looking for some insight on what props you were using. Ken at Prop gods recommended a 15x15 quicksilver q3. That’s a $600 investment(possible fix)that I’m not looking forward to!

 

[bea5454]

Wow. I posted on your other thread and just saw this one. I referenced the 15" swsII, but given you are able to achieve 6100 with the 17" I would likely follow Ken's advice. $600 is not chump change, but I would be highly concerned with a cruise at 5500 or even 5000 - seems like an expensive breakdown not waiting long to happen.

It's a great boat. Best of luck with her!

 

[Pfeehley]

Wow. I posted on your other thread and just saw this one. I referenced the 15" swsII, but given you are able to achieve 6100 with the 17" I would likely follow Ken's advice. $600 is not chump change, but I would be highly concerned with a cruise at 5500 or even 5000 - seems like an expensive breakdown not waiting long to happen.

It's a great boat. Best of luck with her!

Yea he suggested the q3 which is equivalent to a mercury enertia. Definitely don’t want to put anymore strain than I need to on the motor and the fuel burn in 4 trips has been less than desirable.

 

[artodea]

5500 rpms at 28 mph with the 2:1 gears yields 37% slip - wow.
You definitely need to come down in pitch. For reference, see:
https://www.greatgrady.com/threads/gulfstream-f250-propeller-must-read.16450/

 

[Pfeehley]

5500 rpms at 28 mph with the 2:1 gears yields 37% slip - wow.
You definitely need to come down in pitch. For reference, see:
https://www.greatgrady.com/threads/gulfstream-f250-propeller-must-read.16450/

Wow that thread is very eye opening. I’m definitely a believer in the 15 pitch prop now. I guess the 250 guys are running the 15 3/4” version due to extra power and Ken at prop gods recommended the 15” for the lesser power of my 225....either way it sounds like I’m in for a real improvement. Thanks!

 

[SmokyMtnGrady]

If I were you I would still consider turning a 4 blade prop on that boat with the single 225. I have the 228 and the 4.2 liter 250. The 4 blade prop is a real benefit . You should see better performance on the hole shot, cruise RPM ( lower RPMs, meaning better fuel economy)and backing down. Your boat is significantly bigger than mine and yet I have bigger displacement and more ponies. I realize the benefits of going to 4 blades. Ask Ken he will tell you. I had the powertec SW4 before my motor got stollen. When I get the coin after I upgrade my electronics I will be getting another powertec sw4 prop.

 

[Pfeehley]

I bought the 15x15 prop from prop gods. I’ll get it on this upcoming week and report back with results. I did ask Ken about the 4 blade but he was concerned about an already low horsepower to weight ratio and said the 3 blade will have plenty of grip.

 

[bea5454]

I bought the 15x15 prop from prop gods. I’ll get it on this upcoming week and report back with results. I did ask Ken about the 4 blade but he was concerned about an already low horsepower to weight ratio and said the 3 blade will have plenty of grip.

Good luck with it. Expect you will see quite an improvement and gain a lot of engine life.

 

[Pfeehley]

Well the prop showed up yesterday so I ran down to the marina after work and swapped it out.....I cannot believe what a drastic difference it made! I could instantly feel a better bite just putting it in gear pulling out of the slip. She jumped up on plane in at least half the time/distance from before and best of all I was able to stay on plane at 23-24 mph @4500 rpm! I saw 27-28 mph @4800 which was at 5500 with the old prop. Top end improved as well, 38 mph at WOT which also is reduced from 6100 to 5800. I feel so much better now with these lower rpm numbers. This was 2 men, 1 child, both tanks full of fuel and a yeti 75 full of ice and drinks and a not the greatest conditions, plenty of white cap action out in the open river.

Super impressed by Ken @propgods for the spot on recommendation.

 

[Coach1575]

Well the prop showed up yesterday so I ran down to the marina after work and swapped it out.....I cannot believe what a drastic difference it made! I could instantly feel a better bite just putting it in gear pulling out of the slip. She jumped up on plane in at least half the time/distance from before and best of all I was able to stay on plane at 23-24 mph @4500 rpm! I saw 27-28 mph @4800 which was at 5500 with the old prop. Top end improved as well, 38 mph at WOT which also is reduced from 6100 to 5800. I feel so much better now with these lower rpm numbers. This was 2 men, 1 child, both tanks full of fuel and a yeti 75 full of ice and drinks and a not the greatest conditions, plenty of white cap action out in the open river.

Super impressed by Ken @propgods for the spot on recommendation.

I recently purchased a Gulfstream with the same engine. It was a estate sale that I could not pass up. Anyway, I am glad to read that the new prop makes a big difference. Thank you for the information