Propeller Options for Yam 225's

[Alibi II]

I am asking for input concerning props for my twin Yam 225's on our 282 sail fish. We spend 6-8 weeks a year ing MX cruising the sea of cortez. The boat is haeavily loaded and I reach a maximum of 5000 rpms and a top speed of 37 mph wot. I am using the saltwater series of ss props that came on the boat. I get 30 mph at 4200 rpms with the motors trimmed and between 1.1 and 1.2 mpg. I tried the new saltwater II series but got a very heavy vibration in the transom area. My dealer recommended that I return to the stock props.

Has anyone done any exerimenting with different props on these motors?

Would reproping allow me to reach max rpms at wot with the heavily loaded boat inporve my fuel economy?

Would reproping inprove my fuel ecomony at trolling speed 6 mph, 1700 rpm, 1.5 mpg?

 

[jekyl]

There is quite a bit of info on these motors on various grady's but mostly in the 26 - 28 ft range on this forum. I have been trying various pitch 4 blade props with varying results.
Your cruise numbers don't sound as god as they could be. 1.8 mpg at 4,000rpm or just under seems to be achievable in good conditions.

The mercury mirage plus 17" has got great reviews.

I'm running Solas 17" x 4 blades and whilst my fuel usage is down I have sacraficed some speed at 4,000rpm.

What pitch and diam. are your current props? What height are your motors and are you on a mooring?

 

[Alibi II]

propellers

Thanks for the info. I do not keep the boat on a mooring but on its trailer at our home. The only time that it is in the water for an extended period is when we trailer to MX for about 6 weeks. The boat is at the shop having work done on our FLIR and I will post responses as to the actual prop pitch and diameter that I am using and well as motor lengths.

 

[Capt Bill]

I have the same boat and engines as you, but we are rarely heavily loaded, and generally fish with 2 people. I replaced my stock 15 1/4 x 19 Yamaha props with a pair of Power Tech 4 blade, 15 1/4 x 16 polished SS props. My WOT rpm went from 5300/5400 to 6000/6100. A little bit under-propped now, but close. Way better than over-propped as before.

After running them since last April, I have decided to go with Yamaha 15 1/4 x 17, 3 blade. I just got those props today, so I will be making the switch on Tuesday, and see how they run.

I believe that the props I am taking off the boat; the Power Tech 4 blade 15 1/4" x 16" would be just right in your application. I am betting that you presently have the 19" pitch SS on there now. If my new props give me what I want, I shall sell the Power Tech's,, in case you may be interested.