Another thing to consider is an engine wedge. This will allow you to trim the engine in more and get the nose down.
Another thing to consider is an engine wedge. This will allow you to trim the engine in more and get the nose down.
Remember to always log on before heading offshore.
Ok, try again…
You should be able to achieve a good plane well below 20kn – depending on how much you are willing to play around with and/or spend on your motor ‘setup’. Given that 150hp is the max hp, and a 4-stroke (i.e. at the very heavy end of the motor transom weight), you may need a lot of tweaking if you are looking to reduce your minimum planning speed by as much as possible.Originally Posted by Gotty80
Do a search here on motor height, which will reveal a lot of threads discussing this, and the numerous options of achieving a lower planning speed (motor height + ; 4 blade props, foils, trim tabs… all of these etc), and the significant benefits people have achieved from doing this.
Start with the motor height, as this is the easiest (and most likely the cheapest) to rectify – if required. Given by your 20kn remark above, I would ‘guess’ that it might be mounted a hole too low (i.e.) the motor vertical height position is a hole too low. A motor mounted too low definitely gives you a bow-high attitude, and a faster ‘minimum planning speed’ than otherwise could be achieved.
Do not lower your motor height, it will make it worse!
Depending on the interpretations of this terminology, it could mean the same thing.
For a motor with 4 mounting bolt holes as below…
Transom top
|o|
|o|
|o| << is your bolt in this hole?
|o|
For the above motor installation, the “bolt in 3rd hole down” also means the same as the “motor in the 2nd hole down”, meaning the “motor is in the second hole down from the very top position”.
When people say “2nd hole down”, a lot of them are talking about “the motor position lowered down one hole from the top/highest motor position”, not where the bolt is.
Do a search on here and look at the pics/vids on A/V (cav) plate location in the water stream, when at a good cruising speed, and compare to yours and go from there. The dealer could have buried the motor ‘just to be safe’ (well in his mind at least).
Also, if you are only getting 5500rpm max, I would definitely be looking at a smaller pitch prop, especially if you regularly to big trips with a heavy load. Given this, go straight to a 4 blade that provides good transom lift. Most 4 blades provide good transom lift, but only some 3 blades will, and, ‘normally’ a 4 blade will provide better cruising speed economy than a 3 blade. If the dealer can’t help you, give him his prop back & get your money back, and call SOLAS. Give them some rpm/GPS speed data of your existing prop, and they will probably have 2 or 3 four blade props to try… but… sort your motor height out first, as it could change the performance dramatically.
Cheers
Brendon
Last edited by gofishin; 16-03-2017 at 10:03 PM. Reason: re-typed what was lost accidentally!
Thanks Inveratta. Me thinks I'll see Mick down at Coorparoo Marine
Cheers Scottar, I had looked this up myself earlier and thought just the same. 40kg extra way out back is a lot when doing a slow run out as i usually do. i'm pushing a lot of water.
Ive been advised of a larger diameter 3 blade or a 4.
Trimmed out or tucked in going slow on the way out? I was pretty well tucked in
The thing is.
the motor is only 12 months old
still talking to the dealer about this issue as there was no real prop testing.
yamaha dont seem to have a prop option at a lower pitch or 4 blade.
dealer has solas props also but im not sure how they go.
I will look into trim tabs but on the way home it could not ride any better. loves a following sea but assistance into the swell is what i need
My guess is you are heavy as hell and your fore and aft trim is off. My outsider liked having the big esky in the well of the cabin - made a big difference - same hull. Keep the spare 2 blokes right up near your helm area, not sitting in the back corners. Piss the permatrim off - the last thing a fat arsed 18 ft cruisecraft needs is stern lift - they have plenty. If it's not planning at 18 kn there is something pretty bad going on. You sure you speedo isn't set to kph? Mine used to jump onto the plane towing high speed lures all the time at around 11 kn. 18kn was comfortable cruise speed in heavy weather. Even a greyhound like a seafarer will plane at 18 kn - just. What was the load state when you hit 5500 rpm? How did it handle then?
nil carborundum illegitimi
And four blokes on a little boat like that is an awful big load, particularly if you have a heap of fuel and a heavy esky on board. More like a two person boat, really, or three if you need the extra hands trolling for bills.
A 575 a two person boat, really? I might be missing something? I fish 3 in my 5.5mtr boat with no issues at 1770 for 3 days at a time...
Comfortable for 2, ok for 3, crowded for 4. I have a much older boat, a Swiftcraft Dominator, 5.65, but beamy with a better than average amount of deck space for the length, and I wouldn't be fishing four. We fish three fairly often, useful when you are chasing billfish, We also have either a a 110litre esky across the beam, or a large fish cooler bag which stows along one side, leaving 90% of the deck clear.Looked at the pictures on their website, and the useable deckspace is tiny compared to mine. And given the cruisecraft is a deeper vee than mine, which is pretty rounded across the back, it'll be working harder to plane that lot. Unless two of them are occupying the cabin, all that weight of passenger will be aft of amidships.And the size of the passengers matters, too--are his mates all of "generous" proportions? if they all are, he could be going towards a half tonne of human on board. He's simply asking too much of what is a doubtless a very good little boat, IMO.
pic added from Cruise Crafts website. Not my idea of a 4 man boat.
outsider_575_01_thumb.jpg
@gofishin- Yeh that is the motor hole I am on so i will not be moving the motor at this stage. The motor is one above factory setup. (for a normal load)
The Yammi dealer wanted to make sure the motor height was not low before playing with props, so that part is sorted.
So now I'm leaning toward a 16P 3 blade or a 4. The guy i spoke to from cruise craft suggested a 16P as opposed to their usual 17P.
I realize the boat is heavier than most people use them.
Could the permatrim really be a bad thing when I'm bogging down in the arse?
We are bottom bashing straight down and it fishes 4 quite comfortably and 2+ hours each way 4 people helps out alot with fuel costs.
Could anyone recommend a solas prop? or powertech?
Solas make one equivalent to BRP's Rebel TBX propeller (they actually make the prop for BRP as well). 3 blade with big blades designed for mid range cruising economy. Worth a try if they make one to fit. I had to drop 2 inches in pitch to get the right RPM. It is better on my rig than their 4 blade.
Gotty80, I have the same boat (though 2006 model) with a verado 150.I have been trialing motor heights and props over the last 6 months and ended up with a enertia 14 3/4 x 16 pitch. I went down to a 15 pitch in testing but found the 16 was the sweet spot for this motor and lifted the motor one hole from where it was originally. It is worth the effort to do this and I tested and documented each prop change so I knew exactly how they compared.
Happy with the setup now and after these changes I have found the boat more sensitive to trim.
I am also running a permatrim and trim tabs. I find trim tabs are necessary into the swell with this boat and find a small adjustment is all that is necessary to keep it level.
As a guide and I know my motor is a 2006 and not as fuel efficient as a newer model but my best economy is 1.74km to a litre with two POB but no eskys at 4000 rpm.
If you google for them there are two Yamaha performance bulletins on the 575 with the 130 and 150 4 stroke, I get no where near their published figures but may be worth a look to see how you compare. I think they are running a 17 pitch prop in their tests from memory.
Hope this info helps a little bit as I know there was not much to compare to out there when I started looking.
Pretty much as GBC has stated, I don't know how you balance your boat but do your crew all stand up near the helm when travelling into the sea uphill? I find that if you have crew sitting right against the transom in some heavy slop then it will bog down, but move the crew forward and much,much better. It's all just balance, and if you can't get the weight forward to balance out then tabs are the go as suggested. 50nm could be a stretch standing though,
Oh yeh its a fair 2hr minimum jouney. I've an esky in the well up front and a bigger one at the rear the boys sit on in between standing behind the front seats.
Sounding more and more like trim tabs will be a big benefit even after i get the right prop and my revs up.
Thats all good, just one thing at a time for now and i'll get to them one day.
I will definitely try and get a bit more weight forward. last trip i had all the sinkers up beside the helm seats but im sure i can offset a bit more weight yet.
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