2003 MV225 SC with bracket and F225 Fuel Economy

[fishless12]

I just bought the boat described in the subject. I routinely make long runs to fishing grounds so fuel economy is most important. with the stock prop, the boat isn't turning enough revs, WOT is only 5300 and seems to be burning more fuel than the specified fuel usage. I'm not sure of the current pitch, but I'm pretty confident that it needs less pitch. (I'll find out and fill you in when I get a chance)

I'm interested in the best Prop/trim/trim tabs combination for fuel economy.
thanks for all opinions!
Also, do you think those "fins" that mount on the lower unit that claim to boost performance are a good idea?

 

[Porkchunker]

Pick a calm day. With the boat 1/2 full of fuel and normal gear, run the tabs in the full up position and trim the motor so that it is as neutral as possible (anti-ventilation plate is parallel with the keel). Attempt to find the "sweet spot" rpm where you get the best fuel mileage. Then run WOT and record the rpm and the fuel mileage. Let us know what you obtain.

Dave

aka

 

[fishless12]

WOT is 5300-5400 RPM. Fuel usage was 1.4-1.6 mpg running @ 5000. Citing the fuel usage sheet developed by Yahaha for this boat and motor, the performance and fuel economy doesn't come close. All the reading I've done says I should be 6000 rpms @ WOT.

I don't care about holeshot or top end speed. I'm just interested in fuel economy and cruising @ least 23 Kts.

 

[ReelyNauti]

find the sweet spot

on a calm day i too can get 5800-5900 rpm .....

so wait for a calm day an no tabs like the others have said....

the tabs dig in to fuel economy

 

[DaleH]

You need new prop or pitch taken out of that wheel. I wouldn't run any OB if she didn't turn screws ~300 RPMs off max, with std gear aboard, 2 people, and 1/2 or more fuel, maybe 2/3rds on larger tank size. And this ideally should be done in cool weather and when 1st splashed with a clean running bottom.

Most people forget or are oblivious to this point, but ANY normally aspirated combustion motor, gas or diesel, 2-stroke or 4-stroke, WILL LOSE up to 200 RPMs "off normal" when in hot, hot, muggy humid weather ... as the air is thinner. So if you run this test in these conditons, you could be fooling yourself ... and your results.

 

[Brian S]

I just bought the boat described in the subject. I routinely make long runs to fishing grounds so fuel economy is most important. with the stock prop, the boat isn't turning enough revs, WOT is only 5300 and seems to be burning more fuel than the specified fuel usage. I'm not sure of the current pitch, but I'm pretty confident that it needs less pitch. (I'll find out and fill you in when I get a chance)

I'm interested in the best Prop/trim/trim tabs combination for fuel economy.
thanks for all opinions!
Also, do you think those "fins" that mount on the lower unit that claim to boost performance are a good idea?

I have a mercury mirage plus stainless 17p prop which should be ideal for your setup. It's collecting dust in my garage- I'm looking to sell it for $250.