Question About Speed And Props?

[deelan]

hello i bought a 2005 H180 fourwinns a few weeks ago. it has the 190hp motor in it and the dealership told me the boat would go 50+mph, i have opened it up several times and have only got it to about 39. They told me the speedo was messed up so i took it in and they blew out the line. So i took it out again and hit about the same mph. It appears to have the factory prop on it. Is this speed about right for my set up or should i really be getting 50+? Also i have checked the rpms and the seem to be fine (between 4200-4500).. thanks for the info.

 

[blairjbyrd]

Re: Question About Speed And Props?

if the rpms are falling in where the manufacture says then thats it. You could trim it up to get allittle more speep but not much.

 

[jkust]

Re: Question About Speed And Props?

Speaking from experience with the 190 hp and a heavier boat than the 180...your boat should hit 50mph plus a click or two especially with a light gear and fuel load. Your rpms are too low you need to shoot for +- 4800 (take a look at the spec since I am off a bit). The difference between the top end speed when at 4200 versus 4800+ rpms will likely make the difference. I don't know about your particular hull but mine really likes trim. Trimming up to the right level at WOT instantly shoots the speedo up to the max wot mph. I would also grab your car GPS and bring it along as well to get specifics. My speedo is several mph higher than the GPS as high speed but pretty accrate at cruising speeds. What pitch is your prop? Is it the 14 1/4 21pitch aluminum? Dumb question but are you positive you have a V6 and not the 4 cylinder?

 

[hwsiii]

Re: Question About Speed And Props?

Dee, what make, manufaturer, diameter andpith is the prop you have on it now.


H

 

[QC]

Re: Question About Speed And Props?

You could trim it up to get allittle more speep but not much.

Trim can make more than a 5 MPH difference. Very significant. Weight balance, prop (defer to hwsiii) engine condition, prop condition, bottom condition, beer, friends, mothers in law, fuel, water, tools, annnnnnnnndddddddd, overly optimistic salespeoples can all be significant . . .

 

[4JawChuck]

Re: Question About Speed And Props?

If I had a dollar for every boat I got into that did 40 mph WOT but the owner said it did 60 mph I would be a rich man.

 

[deelan]

Re: Question About Speed And Props?

Im not 100% on the prop specs, and i know that is important info. Really im not to concerned with hitting 50+mph however since they told me that i wanted to make sure nothing is wrong with the engine/prop. I do know when we demo'd the boat he told me when im full throttle to trim up about 1/4 the way up and that does give me a few more mphs (about to 39mph). Since i was told not only by the sales guy but also by the mechanic that this boat should hit these speeds is what concerns me. Im hitting cedar creek this weekend and i will look at the prop and get some more info (prop specs). Thanks for the info.

 

[deelan]

Re: Question About Speed And Props?

Sorry, also the last time i topped out was me, my wife, and my youngest son onboard (less than 300lbs) and maybe a 100lbs in gear so its a light load..and yeah its a v6

 

[jkust]

Re: Question About Speed And Props?

I will be curious to hear the prop specs and don't forget your GPS. Take a couple of pics of the rig while you are at it...we like pictures.

 

[deelan]

Re: Question About Speed And Props?

ok, so i dont see the kind of prop it is, but it says 14.3x21 on the side of it.

 

[hwsiii]

Re: Question About Speed And Props?

Dee, I have read everything you have posted, but it is only bits and parts of information, please fill this out and I will help you as muh as I an.

Iboats Boat and Motor Info

1. Year, make and model of boat
2. Length, width and base weight of boat, look for boat decal on back of boat
2a.What is the maximum recommended HP for your boat
3. Number of people and gallons of gas normally on boat
4. What do you use the boat for
5. Is it a Deep Vee and if so how many degrees of deadrise
6. Year, make. manufacturer and model of motor
7. HP and gear ratio of motor IMPORTANT
If you don?t know the ratio, you need to pull the plugs out and put a piece of tape a c ross the prop and the lower unit and then cut it between the prop and the housing and turn the motor until the tape lines up with each other, it is easier if two people do this, so one can watch the prop while the other counts the revolutions of the motor
8. Manufacturer?s recommended Wide Open Throttle (WOT) range
9. Anti-ventilation Plate height above keel of boat if it is an outboard in inches, use a board under the keel and stiking out to the anti ventilation plate for a referene
10. Is it a bass boat or does it have a pad bottom
11. Does it have a hydrafoil, dolefin or trim tabs
12. Make, model, diameter, pitch and whether SS or aluminum prop
13. WOT RPM and speed from your current prop and how much gas and how many people were in the boat for the test data and is the speed by GPS. Make sure you trim the prop up until it starts ventilating and then just trim in until it quits ventilating. If you do not have a tach you can buy a Tiny Tach for $ 50
14. Are you at sea level or a higher elevation, give us the elevation in feet
15. Has your motor been tuned up lately and have you checked that the carburetor butterfly is opening all the way, checked compression, and looked at the plugs and checked spark, all of the foregoing could be the reason your prop is not attaining full RPM
16. How long has this prop been on the boat and why, at this time, do you think it is the wrong prop
17. Does the prop show any damage that you can see
18. What problems are you trying to cure or what are you looking for the boat to do that it is not doing the way you think it should or to your expectations
19. If you are trying to attain a better cruising speed and fuel savings or trying to attain a faster speed I will want you to take your boat and run it with 1 or 2 people and give me the RPM and speed readings starting at 3,000 RPM in 500 RPM increments all the way to WOT.

REMEMBER, The numbers I give you will be NO better than the information you give me

The only thing I ask of you is to come back and give me a report of WOT RPM and speed for my database.


H

 

[deelan]

Re: Question About Speed And Props?

yeah im sorry about the lack of info H, im pretty new to the boating world. Just trying to figure it all out. I will have to round up all that info...thanks.

 

[hwsiii]

Re: Question About Speed And Props?

I understand Dee.


H

 

[TilliamWe]

Re: Question About Speed And Props?

I highly doubt it will run 50+. But 39 is not fast enough. Could be operator error, could be a prop issue. Fill out the huge list of info and see what it comes up with.

What speed did the speedo show on the sea trial?

 

[ramster]

Re: Question About Speed And Props?

Don't just trim 1/4 on the gauge, when at WOT, start trimming up and take notice to how the engine sounds, and watch the tach and speedo. If you trim to far, you will hear the way the engine sounds, and maybe start to get a big rooster tail, and your speed will drop. Once you reach that point, trim back down a little at a time until you get max MPH, then look at your trim gauge.

 

[hwsiii]

Re: Question About Speed And Props?

Dee, in my opinion you are just short by a ouple of MPH, and the dealer is either lying to you or doesn't know anything about the speed of the boats he sells, whih I find very hard to believe. If that dealer has sold anymore of that exat boat ask for the name of a person who bought it and see what speed they are getting. But I GUARANTEE you he won't have anybody that an say they get over 42 MPH with that setup you are running. I found a lot of the information about your boat myself and plugged in the numbers and it won't do over 42. Don' get me wrong, I only make errors when I am breathing, but I am right about this. And be sure and trim it out like ramster says to, he is right about that.


H

 

[QC]

Re: Question About Speed And Props?

One last note about trim . . . she will be fastest when the bow is up as high as possible without porpoising (rhythmic bouncing of the bow up and down). If you get a rooster and a rise in RPM before she porpoises, then you might try shifting some weight aft. Experiment a little, there are no hard and fast rules about trim other than higher is faster and don't exceed trim limit which should be limited by the drive itself, not the gauge necessarily. Read here about the difference between trim and tilt or check the operators manual if you have one. If you don't, PM me your Make ( not sure if this is a Merc or a Volvo) and email addy and I'll send the closest thing I've got.

 

[deelan]

Re: Question About Speed And Props?

Alright we took it out this weekend and i lined up several different times with my buddy's boat the conclusion we came up with is the seepdo is about 6-8mph off (lower) than what his boat was reading (08 4winns). So off to the shop tomarrow. thanks everybody for your input and we are taking it out again labor day weekend and i will let everybody know what the "real" speed is..thanks again

 

[hwsiii]

Re: Question About Speed And Props?

I don't understand what that statement means, are you saying you are getting your speeds only from mehanial means and not from a GPS. Beause anything from speedometers is untrustworthy, they an easily be off by 10 or 12MPH.


H

 

[deelan]

Re: Question About Speed And Props?

yes. i do not own a GPS.