www.iFourWinns.com

I'm trying to decide if I need new props or not. 2000 four winns 298 vista with 5.0. Top speed seems to be 36 mph at approximately 3200 rpms. The boat doesn't seem to get up on to plain very easy to me. I'm also being told that my rpms should be higher. So I'm just looking for some input. I'm not sure what props are on the boat now. I'm assuming they are the factory pitch props

That's the first thing to find out. Without knowing what you have, trying other props is like playing darts in the dark.

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Mike
2005 Four Winns 230/240
VP 5.7GXi/DP
1998 F-150 XLT
Boat Pic

3200 rpms is way too low. Assuming your tachs are working properly.
If your engines are running fine with new plugs, wires, fuel separator, etc... then I would say your props are too large in pitch.

Give us some more info on your exact setup.
Volvo or Merc engines?
Which outdrives?

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The Dance II
2007 278 Vista
6.2L Mercruiser

Engines are volvo 5.0 gi and outdrives are volvo sx I believe. They've been repainted. They have dual props. I swing by and get the numbers off the props in just a bit

Current props are F5's.

5.0's most likely came from the factory with F4's. But I don't think that alone explains the top RPM's being so far off.

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Mike
2005 Four Winns 230/240
VP 5.7GXi/DP
1998 F-150 XLT
Boat Pic

I also have a 2000 298 with 5.0 Gi motors also have dual prop You definitely should be getting a lot higher rpm's in that my props are F5 also. The only thing I seem to get is right around at 3000 RPM when I have 8+ aduls on it takes a minute to get up on plane. I thought I read the F5 was the stock prop. If anyone knows anything different let us know

Then I must have something else wrong. Both motors are new less than 20 hrs. New fuel pumps on both.... hp and lp. At max I’ll get 3600 rpms. This puts me at about 35-38 mph with two people on board . If I have 8 people on board I’m not getting on plane period. When I try to throttle up and get on plane neither engine will go over 2000 rpms. They will reach 2000-2200 and stay there. It will eventually climb and take off. If I keep pressing the throttle down the both engines will choke out. I was told I needed to reprop. Glad I found this out before I bought new ones. Any suggestions

I just checked the "Fast Facts" on fourwinns.com for a 2001 Vista 298. It says that twin 5.0Gi/DP should have F5 props and should achieve 30mph at 3500rpm, 37mph at 4000rpm, 43mph at 4500rpm, and 48mph at WOT. For the higher horsepower twin 5.0Gsi/DP should have F6 props (more pitch) and should achieve 32mph at 3500rpm, 40mph at 4000rpm, 46mph at 4500rpm, and 51mph at WOT. These numbers are usually pretty accurate with maybe 2 people on board and 1/2 tank gas.

If you are going 35-38 mph at 3600 rpm, those numbers indicate that you have too much prop pitch. However, you said you have the correct F5 props. That seems to leave the following options:
1. You do not truly have F5 prop set (did you check both props of both engines?)
2. You have drives with a non-stock gear ratio
3. You have bent props (bent in the direction of more pitch)
4. Your Tachometer is off
5. Your speedometer is off

I would question the power of your engines, except that 35-38mph is pretty high power for only 3600 rpm. Does seem to indicate being over-propped.

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"Knot Easy" 2000 Horizon 240 Volvo 5.7GS /SX
tow: 2017 Honda PILOT EXL-AWD
prev. boats:
'87 Chaparral 198CXL 4.3 OMC Cobra
'69 Jetstar 16ft Ski Boat, 115hp Yamaha
'68 Aluminum Jon Boat, 3hp Sears
'64 Water Wings

Yes I’ve checked both props. And they are both f5s. As far as different gearing in the outdruves I have no idea. Only thing I’ve done on the outdrives was replace all u-joints, paint and top off with oil. Not sure about the props being bent. I do have another f5 prop that had never been mounted . I could compare. Tachs being off totally possible. Speedometer off totally possible but when checking speed I typically use gps on my phone. Another symptom that I forgot to mention is how each engine runs at a different rpm while cruising to get the prop tach to be even and on zero. This tells me that the tachs are incorrect because I generally go off of sound of the engines. I can hear when they are in sync and running very close revs. Still can’t figure out the lack of power on take off though

There should be a label or plate on each drive indicating its gear ratio.

One other slim possibility (very slim) is that someone in the past had those F5 props modified. A good prop shop can tune props to meet customer requests - even if the customer only *thinks* they know what they need.

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Mike
2005 Four Winns 230/240
VP 5.7GXi/DP
1998 F-150 XLT
Boat Pic

Ok i need to check into this. I bought my 2001 298 from Colorado and found out the original F6 props were switched to F4 at some point. The boat was sold in florida and then went to Utah/Colorado and then to me here in Michigan last June. Seems to run good (IDK my first boat). I have twin 5.7gsi with the DP-SM duoprops. Best I saw was around around 43 to 44mph on Gps (navionics app). The stock tachs were around 4500 to maybe 4900. Stock speedo does not work. This boat is supposed to run 49 to 51mph at 4800-5000 rpm I believe. Should I buy the F6 props? I assume they were changed due the elevation out in Utah? I was thinking of running boat next year with my Laptop (Diacom) to get an accurate digital RPM's -I don't trust the 16 year old analog tachs. What is the difference running the F6 prop? Will I get more RPM?

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2001 Four Winns 298 Vista
Twin 5.7 Volvo Penta GSI DP

No, you’ll get fewer RPM’s. The higher the number, the steeper the pitch and the more HP and torque (larger engines) are required to turn them at the same rpm under the same load.

Always select props to achieve your target RPM’s and then if you aren’t attaining target speed, you know the problem is elsewhere (or the speedometer is inaccurate). Also note, FW’s specs on props, RPM’s, and speeds are typically very accurate so you should be able to rely on them to select the correct props.

It sounds to me like the boat was originally propped wrong for high altitude (or a previous owner tried to “fix” it by switching to F6’s - a common mistake), and then a different wrong set was installed for sea level operation. I’d recommend matching the factory spec as a starting point and then work from there.

Also, as you can see it’s worth having working, reliable tachs in a boat; they're really more important than a speedometer in a practical sense.

I would expect twin 5.7’s to move that boat along nicely.

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Mike
2005 Four Winns 230/240
VP 5.7GXi/DP
1998 F-150 XLT
Boat Pic