330 F250s Top End, RPMs

[grady33]

I have a ‘06 330 with F250s. Engines have 1400+hours on them. Boat has everything. Lee outriggers, freezer box, bow thruster, diesel gen - everything.

I generally cruise at 4800 RPMs at 29-32 MPH. I like to run it wide open throttle a minute before we get back to dock from offshore trips. With full load and 5 people onboard, top end with engines down is 5400 RPMs and 36-37 MPH. My buddy has the same boat but 2007 with 800 hours or so. He purchase 2 years ago and the dealer did a full decarb of engine as part of sale. He seems to get a little more RPMs 5,600-5,700. Just wondering what other 330 owners w/F250s on the group are seeing???

I can get higher RPMs with a slight tilt of engines.
Thanks!

 

[HMBJack]

I'm the exact same as you. 2006 330 with F250's (2,400 hours now).
You, like me, will probably achieve 5,700 RPM's WOT if the boat is light and in calm water.
Perhaps the only difference besides weight and sea condition to the 2007 330 is props.
I cruise at 4,300 to 4,400 RPM's doing 22-24 knots (25-28 mph) at 25-27 GPH with my 4 Blade 16 pitch props.
I use Ring Free alot and very rarely throttle my boat above 5,000 RPM's but that's me.

 

[grady33]

I'm the exact same as you. 2006 330 with F250's (2,400 hours now).
You, like me, will probably achieve 5,700 RPM's WOT if the boat is light and in calm water.
Perhaps the only difference besides weight and sea condition to the 2007 330 is props.
I cruise at 4,300 to 4,400 RPM's doing 22-24 knots (25-28 mph) at 25-27 GPH with my 4 Blade 16 pitch props.
I use Ring Free alot and very rarely throttle my boat above 5,000 RPM's but that's me.

Yeah I have 3 blade prop and nearly always stay at 4,800 RPMs. Best fuel mileage at that RPM range. You’re probably right but was wondering why a buddy of mine is able to get higher.

 

[Hookup1]

You should be turning closer to 5,800 RPM. It's probably over propped for your heavily load boat. My mechanic (Yamaha certified) recommends ring free with every fill up and to run the boat WOT for a few minutes when coming in to blow the carbon deposits out.

 

[Toothpick 10]

You keep your motors all the way down when on plane? If so, why? With the GW hull, the most efficient way to run is with the motors trimmed up as far as you can without the props ventilating, once on plane. That approach will give you higher rpms and more efficiency because less of the hull surface is in the water.

See video for instruction:

 

[grady33]

You should be turning closer to 5,800 RPM. It's probably over propped for your heavily load boat. My mechanic (Yamaha certified) recommends ring free with every fill up and to run the boat WOT for a few minutes when coming in to blow the carbon deposits out.

Thanks. Have always used ring free and I do run it wide open for 30 secs to a minute. Maybe I’ll try to do it longer and see what happens.

 

[grady33]

You keep your motors all the way down when on plane? If so, why? With the GW hull, the most efficient way to run is with the motors trimmed up as far as you can without the props ventilating, once on plane. That approach will give you higher rpms and more efficiency because less of the hull surface is in the water.

See video for instruction:

Thanks. I do trim them up. Was just keeping them down fir the purpose of comparing what others are seeing. I do get higher RPMs when trimming up.

 

[seasick]

I don't see any problems at all. First of all, the wot revs are in the spec range. Folks get fixated on max revs but things are more complicated than that.
The fact that you get higher revs when the motors are tilted is not necessarily a good or bad sign. If the revs go up AND the speed goes up, that is an indication that your trim is nearing optimal settings for current conditions ( pardon the pun)
If you revs go up but speed doesn't, that's not a good thing and indicates a prop issue or motor rigging issue. ( or too much up trim)
You can't really compare your numbers to another similar boat/motor without keeping all other variables the same, such as load (people, gas, equipment and gear) , weather, seas, bottom condition, canvas etc.
You also must make sure that trim tabs are all the way up.
Remember that 5 bodies on board is equivalent to having an extra 150 gals of gas or looking at it another wat, 150 gallons of gas is like having an extra 5 'typical' adults on board.

 

[grady33]

I don't see any problems at all. First of all, the wot revs are in the spec range. Folks get fixated on max revs but things are more complicated than that.
The fact that you get higher revs when the motors are tilted is not necessarily a good or bad sign. If the revs go up AND the speed goes up, that is an indication that your trim is nearing optimal settings for current conditions ( pardon the pun)
If you revs go up but speed doesn't, that's not a good thing and indicates a prop issue or motor rigging issue. ( or too much up trim)
You can't really compare your numbers to another similar boat/motor without keeping all other variables the same, such as load (people, gas, equipment and gear) , weather, seas, bottom condition, canvas etc.
You also must make sure that trim tabs are all the way up.
Remember that 5 bodies on board is equivalent to having an extra 150 gals of gas or looking at it another wat, 150 gallons of gas is like having an extra 5 'typical' adults on board.

Good points all around. Thanks and engines perform well so I’m going to leave it be and run them for now.

 

[grady33]

Ran the boat yesterday down 200 gallons of fuel and only 2 people on board. Got up to 38 MPH at 5600 RPMs. Sounds like I’m all good!