Tournament 225 performance

[jail]

I have a 2006 Grady White Tournament 225 with an F225 I have owned for about a year. The Yamaha performance bulletin shows at
4000rpm 29.4 mph 3.34 mpg
5000rpm 37.6 mph 2.98 mpg
6050rpm 45.8 mph 2.35 mpg
My results are
4000rpm 20mph 2.3 mpg
5000rpm 30mph 2.4 mpg
6100rpm 38mph 2.2 mpg
Boat is bottom painted but clean. Just the wife and I on the boat we weigh about 315 lbs combined, and light gear. Bracket is dry. Prop is the recommended SWII 17x15 1/2 and has been tuned. What really surprised me is that the results don't change significantly with a third tank of gas or a full tank of gas. I seem to get between 2.2 and 2.4 mpg no mater what speed or rpms I run at. The boat feels best running at about 4700 rpm and 27 mph. According to the performance bulletin I should be running much faster at that rpm.
Numbers are in calm ocean, no trim tab, engine trimmed.
I would love to hear fromm other Tournament 225 owners as to their real world performance numbers

 

[Parthery]

Are you getting your MPH from your GPS or from the speedo? The speedo pitot on the front of the lower unit may be clogged. A tiny drill bit or piece of fishing wire leader will clean it out.

GW performance numbers always seem to be a bit optimistic....that said, my 225 (same hull, different cap) with a 225 OX66 turns 4300 rpm at 33 MPH on the GPS. And I'm getting right around 2.5 MPG based on the fuel flow meter.

The 2 stroke tops out at 5500 RPM.....I've never seen 45 MPH unless it's on the trailer. I'm closer to 41.5- 42 at 5500.

 

[Finest Kind]

Something does not make sense here... why is your stated fuel economy at 6100 RPM almost the same as it is at 4000 RPM?
Faulty gauge?

 

[jail]

Exactly why I am confused Finest Kind.
My speed is from my GPS
RPMs and fuel flow are from Yamaha gauges

 

[bea5454]

Are you (I) calculating mpg based on your displayed gps speed and the flow rate from Yama gauge (better) or (II) reading the mpg from the Yama gauge?

The Yama gauges on both my gulfstream and current utilize the pitot tube, not gps, for purposes of calculating mpg.

In any event, though I wouldn't expect to meet the performance bulletin (even more so with bottom paint) performance seems lacking. My 2006 gulfstream (much heavier and beamier) with F250 would get 2.2 mpg heavy and would occasionally see 2.4 mpg light at 4600 - 4800 "cruise", 25-28 mph depending on load/conditions, top speed 36-37 at 5700.

Has your vst filer been checked/serviced?

Good luck.

 

[jail]

I get my RPMs and fuel flow from the Yamaha gauges . I calculate mpg from GPS speed

 

[Finest Kind]

Exactly why I am confused Finest Kind.
My speed is from my GPS
RPMs and fuel flow are from Yamaha gauges

Obviously, something is not accurate, I'd suspect the Yammie gauges.
NO WAY an engine turning at 6100 RPM is going to burn almost the same amount of gas as one turning at 4000 RPM!

 

[glacierbaze]

How does your fuel gauge compare to actual gallons required at fill up?

 

[jail]

"Obviously, something is not accurate, I'd suspect the Yammie gauges.
NO WAY an engine turning at 6100 RPM is going to burn almost the same amount of gas as one turning at 4000 RPM!"

At 6100 rpm it burns way more fuel per hour but is going almost twice as fast so about same MPH

 

[jail]

I have discovered that I have a 30" shaft motor on this boat. All information I can find, including an original brochure for this boat states it should have a 25" shaft. I am surprised it works as well as it does.

 

[Tuna Man]

I saw and responded on the other site the other day. If this is in fact a 30" shaft I am not aware of an easy fix. You could purchase a jack plate, but as far as I know they are not really designed for Grady style boats (more like go fast bass boats in calm waters). Not sure what your options are with regard to lower unit/ mid-section modifications. I think the lower units are the same (with a different shaft length) and the mid-sections are five inches longer (taller) on the 30" units as compared to the 25" units.

Please let us what you decide to do.

 

[Doc Stressor]

I replied to your post on THT as well. The picture that you posted does not look like a 30" shaft. These are not common and I only see them at the center of triple rigged engines. I don't see the 5" extension in your picture.

Why do you think you have a 30" shaft?

 

[Parthery]

Like Doc, I too responded to your post on the other site.

Are you sure it's a 30"?

Can you post a pic of the prop?

 

[jail]

I have determined that it is not a 30" shaft. Not sure why the mechanic told me that.

 

[ocnslr]

The early F225s had a gear ratio of 2.0:1, and that changed to 1.75:1 in about 2006. Are you sure what gear ratio you have? If not, pull the plugs and rotate the engine one complete revolution, while carefully determining the partial revolution of the prop. OR, in forward gear, rotate the prop one revolution and carefully determine if the engine (flywheel) rotates 1.75 revolutions, or 2.0 revolutions.

Is the performance bulletin you refer using an engine with the same lower unit ratio as your engine? If not, then the prop used for the performance test will not be correct for your engine.

Are you sure that your engine should have the SWSII, and not the original SWS? Big difference in design and performance.

 

[jail]

The early F225s had a gear ratio of 2.0:1, and that changed to 1.75:1 in about 2006. Are you sure what gear ratio you have? If not, pull the plugs and rotate the engine one complete revolution, while carefully determining the partial revolution of the prop. OR, in forward gear, rotate the prop one revolution and carefully determine if the engine (flywheel) rotates 1.75 revolutions, or 2.0 revolutions.

Is the performance bulletin you refer using an engine with the same lower unit ratio as your engine? If not, then the prop used for the performance test will not be correct for your engine.

Are you sure that your engine should have the SWSII, and not the original SWS? Big difference in design and performance.

Interesting point. The test engine had a 2.0:1. My engine is a 2006 model. I need to check the gear ratio. I was told the prop I have is the original. Not everything I was told has proven not to be true.

 

[Green Pond]

Are you getting your MPH from your GPS or from the speedo? The speedo pitot on the front of the lower unit may be clogged. A tiny drill bit or piece of fishing wire leader will clean it out.

GW performance numbers always seem to be a bit optimistic....that said, my 225 (same hull, different cap) with a 225 OX66 turns 4300 rpm at 33 MPH on the GPS. And I'm getting right around 2.5 MPG based on the fuel flow meter.

The 2 stroke tops out at 5500 RPM.....I've never seen 45 MPH unless it's on the trailer. I'm closer to 41.5- 42 at 5500.

Where is the speedo located?
Thanks

 

[suzukidave]

Interesting point. The test engine had a 2.0:1. My engine is a 2006 model. I need to check the gear ratio. I was told the prop I have is the original. Not everything I was told has proven not to be true.

if your engine has a 1.75:1 gear ratio then you should be going faster at any given rpm than a boat with a 2.0:1, not slower. you would need to have a gear ratio of around 2.8-3.0:1 to explain your results all other things being equal.

also, 4000 rpm to get to 20 mph makes no sense at all. 38 mph at 6100 rpm is closer but it still means 23% slip. the yamaha test you cite yielded a prop slip of 10% at 4000 rpm and 6% at 6050. that sounds closer.

one thing that confuses me is that your engine can still get out to 6100 rpm but only 38mph. if it was running into that much hull drag i'd expect you not to be able to make it anywhere near 6100 rpm. that suggests to me it is not a drag issue and is a prop spun issue to me or some kind of weird frankenleg gear ratio or tach error.

first thing you should do as another has said is turn the prop in gear by hand counting the rotations until it turns the flywheel a single full rotation (use tape for marks). that will tell you for sure the gear ratio on this boat (keep in mind people swap legs on motors). pull the plug leads and turn the battery off before you do this to avoid accidentally bump starting.

assuming you come up with a gear ratio numberof 2:1 or less, i would then check if your prop is spun. make two aligned marks on your prop hub with a sharpie on the metal one to the inside and outside of the rubber hub and inspect after a sea test to see if they remain lined up. if they do not then your problem is the propeller is slightly spun.

if that doesn't work i'd suspect the tach is faulty or set wrong and is overstating your true rpm. i can't see how the boat would get to 6100 rpm with that much drag

 

[jail]

Thanks Suzukidave, I will check those things. I am still confused about this, as this motor runs nice and everything seems good except the speed. I agree I should be planing nicely at 4000 rpm., rather than barely planing. Don't really understand what you mean by "prop is spun". Boat is out of water for season now. In the spring I am going to fit motor with an MNEA network so I will have gages on my gps screen, and rule out my tach being off.

 

[suzukidave]

Thanks Suzukidave, I will check those things. I am still confused about this, as this motor runs nice and everything seems good except the speed. I agree I should be planing nicely at 4000 rpm., rather than barely planing. Don't really understand what you mean by "prop is spun". Boat is out of water for season now. In the spring I am going to fit motor with an MNEA network so I will have gages on my gps screen, and rule out my tach being off.

i see reading more carefully now you don't mention the year of your motor that i thought was a 2007. are your existing gauges taking the data feed from the engine computer? that would change my assessment a little. on an older rig the fuel flow and tach would be measuring two totally different things independently so for them both to be weird suggests a real world problem.

anyway, the spun hub thing is simple to check and is worth doing to rule out before handing this to a mechanic.

a propeller has a rubber ring that is friction fit between the propeller body and the central hub. if you hit something with the prop the rubber is designed to "spin" on the hub so there is no damage (or less damage) to your leg and engine from the prop suddenly being stopped from turning.

if you hit something hard enough to permanently break the rubber friction fit on a prop it is called a spun hub . most of the time this is very obvious because when you try to run the boat afterwards your prop just slips and you go nowhere. however, sometimes a damaged prop hub only slips just a little or only under heavy load which causes symptoms of the engine seeming normal at low rpm but revving too high at higher speed. the trigger point for symptoms is usually either while trying to plane or at very high rpms.

your situation does not perfectly fit my idea of a spun hub because of the weird fuel consumption and because you start to get the problem when planing but can still get past the planing and still achieve a somewhat respectable top speed. however, i i would check it out to rule it out.