F150 wot 5200

[Aquamort]

Hey all,

I have a 2006 F150 on a Bertram 20 that i recently purchased. WOT is 5200 which i feel is too low. It also has terrible hole shot and will fall off the plane in swell under 20knots. The engine is really working hard.

Another 50 or 75 hp would be great but thinking changing the 17p prop to a 15p? My top speed is around 33knots at 5200rpm. It is used offshore so would like to sit on 20-25 knots.
Cheers.

[pstephens46]

Must be a heavy boat.

[TownsendsFJR1300]

Sounds like an improper prop issue as mine came with the wrong prop.
Same issues, a dog getting out of the hole, WOT was 5,000-maybe...

I have a similar vessel (20'4" Angler CC ) and exact same engine.

With the correct SS prop WOT is 5900/6000 trimmed out, 46 MPH.
4,000 RPM, cruise speed is 30 MPH.

Someone can deceiver the prop code (size/pitch (I don't know off hand):




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[Aquamort]

Yeah my boat is pretty heavy. This is the third time ive had it out, this time with 4 men and dive gear so loaded well.

Id say your prop is a 17p by looking at those numbers...

[TownsendsFJR1300]

Yeah my boat is pretty heavy. This is the third time ive had it out, this time with 4 men and dive gear so loaded well.

Id say your prop is a 17p by looking at those numbers...

Yep. You have to get that engine RPM's up to close to 6K loaded.

It makes such a BIG difference.

Plug in your info at this Yamaha site, it's pretty accurate:

https://yamahaoutboards.com/en-us/ho...ance-bulletins

[Aquamort]

They all seem american boats that i dont know? Do you know what would be comparable to mine?

** think a Steiger craft may be similar. It has a 15p prop which is what i was thinking i would need other than a 200 or 250hp!

[TownsendsFJR1300]

They all seem american boats that i dont know? Do you know what would be comparable to mine?

** think a Steiger craft may be similar. It has a 15p prop which is what i was thinking i would need other than a 200 or 250hp!

Go back to that link. There's an arrow (to go to the right) for other applications.

The "Express" version/pic, seems to be similar to yours..


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[Aquamort]

The xpress im looking at looks like small bass boats? I must be doing something wrong here.

[pstephens46]

Provided the engine is running well and there is no extra weight hiding somewhere a lower pitch is about all you can do. Engine mounting height could make a difference. Pity you can't test a 15 somehow before buying.

Wonder if bracket mounted motors need to mounted a little higher? Need that PropGod guy....

[Aquamort]

Provided the engine is running well and there is no extra weight hiding somewhere a lower pitch is about all you can do. Engine mounting height could make a difference. Pity you can't test a 15 somehow before buying.

I know...ive started looking for a 2nd hand one etc. Ive raised the motor since buying it. Cav plate is now about 2 inches above keel on a 2 foot set back pod. I reckon it could still go higher but is on highest hole. it definitely made a difference though as i dont have to use trim tabs to stop it porpoising when trimmed out now.

[TownsendsFJR1300]

The xpress im looking at looks like small bass boats? I must be doing something wrong here.

I think your in the wrong section. Get to "the prop selector" section. It'll bring up some boat pic's. To the right, is an arrow to scroll for more pics/boats.

The "express" looks about the same as yours...





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[Aquamort]

ok got it now....its saying a 13p..***

[pstephens46]

Interesting. That boat looks to be a late 1960's model. Very stout looking.

There is a guy in FL that has loaners. But maybe not overseas.

[Aquamort]

Theres a company here is Australia called Solas who i believe will let you test props before you buy. I am waiting for them to get back to me.

You mean mine looks late 60's? Its possible...im not sure of its history. It has solid timber stringers i know (not ply). Carribean built bertrams here is oz under licence for a long time...then they built under there own name and also Pride. I believe the hull was copied alot too with other brands such as Penguin and Hunter

[Aquamort]

UPDATE:

O i was able to borrow a SOLAS 14 1/2 stainless 4 blade 15 P (Fits perfect - just need to use the merc thrust washer). Unfortunately thought it made bugger all difference. Slightly better if anything. pushed 5300 trimmed right out doing 33 -34 knots. So maybe gained 100 rpm at most. Very disappointing as i thought i was on a winner.

I will recheck outboard height on pod - its on as high as it can go now...if still too low will have to come up with something then.....

I will check that im getting full throttle! It just doesnt seem right that i go down 2 prop sizes...granted one is a 4 blade.....and have minimal change!

Open to other ideas......Motor idles and seems to run fine but ill prob do a compression test anyway but will be surprised if thats an issue....