Speed of your 4.2m tinny + 4.5m

[kind_cir]

Hanging in there in hope to get a good deal on a boat at the tinny and tackle show at the end of the month.
I know all will say go the 40hp in a 4.2-4.3m tinny over the 30hp, but what is the real difference in performance ?
It seems all shops package these boats with a 30hp, i assume to keep the ticket price down.
I will prob go a 40hp anyway, but am just curious as to the difference, so if you can post up your WOT speeds and cruise speeds of your tinnies with 30's and 40's that would be great.
Also looking at 4.4-4.5 tinnies so can you please post up your speeds with 40hp's and 50's.

Thanks

[dreemon]

I had a 4.1 brooker with a 40 2st mariner, max speed was 64 kph 6 thou rpm, cruise would be just under 50.

[TheSaint]

Here's a thread i started on the 40hp yamaha 2 stroke which may help..

http://www.ausfish.com.au/vforum/showthread.php?180804-Yamaha-40hp-performance


I can tell you from my experience is that there is about 10-12kph in WOT top end speed from 30hp to a 40hp..

[Scott79]

In addition to Saints thread, I am sure there is another one very similar also.

I had a 2003 Quintrex Dory 445, with 40VMHD (3 cyl / tiller steer / pull start) and I could consistently get 44km/hr, and load didn't make much difference. Didn't have a tacho, but sounds like a few people are getting into the mid 50's, so I probably could have experimented a bit with props and motor height etc and get some improvement.

At the time when I bought mine the option of going to the 50hp was only about $850, but I had thought that the 40 would be adequate, which in all honesty it probably was. Although it is a bit of a contradiction, if I was to buy the same thing tomorrow I would definitely get the 50. You don't hear about many people wishing they had less HP.

Scott.

[purnong]

I've got a 4.5 Brooker 450 Seaman tiller steer with a 50HP Tohatsu TLDI and the best speed I have had so far is 67Kmh

[antg2378]

The Blue Fin Barracuda 4.5 I had had a 50hp Mercury Mariner. I never revved it higher than 4200rpm, at that rpm it was doing 43km/h according to the gps.

[Eug]

4.2 bluefin with a 40hp 2 stroke and i sit on 44km/hr at WOT

[nigelr]

4.2 stessco catcher 30hp tohatsu 48kph one-up on the river.
sufficient for me, but would go a 40 for inshore/bar crossing more than one-up.

[kind_cir]

4.2 bluefin with a 40hp 2 stroke and i sit on 44km/hr at WOT


4.2 stessco catcher 30hp tohatsu 48kph one-up on the river.
sufficient for me, but would go a 40 for inshore/bar crossing more than one-up.

What's wrong here ? Similar boats but the 30hp is faster than the 40hp :o ????

[LittleSkipper]

The speed of a 4.2mt tinny + 4.5mt = As fast as an old china bath tub! ;D

[74fpv01]

G'day .

2001 4.5 mtr savage safari 40 h 4s Honda. 2 up full fuel and medium esky. Top speed sits around 19/20 knots.

When we bought it it had a 4 blade prop and the performance was crapola. From memory it was flat out getting up to 15 knots and took forever to get out of the hole.

Changed to a 3 blade prop and made a massive difference.

Cheers.


Sent from my iPhone using Tapatalk

[Blaster Bretty]

Hey kind mate!!! the main difference between the 2 motors, 30hp vs 40hp, is that with the 30 you will hop in it and go WOT most of the time, put the mrs and a kid or 2 in there and you will go WOT all the time!
Now with the 40Hp on the same boat you will be WOT when shootin out the hole and then wind her back when on the plane! the 40 just gives you more grunt to play with but not neccassarily a great deal more top end, that comes with prop pitch's and motor height adjustment!
with standard props from new you could bet you'll do about 45 -55kph... play with the props and heights and you may to 65kph+
Hope that helps!

[pig75]

My 4.1 brooker safari with 2 people with 30 2 stroke Suzuki 45km/h fresh water. PS thats with mixed fuel thats over 6 months old

[marty+jojo]

4.2 bluefin with a 40hp 2 stroke and i sit on 44km/hr at WOT

I have the same set up and I get 51kph on the GPS.
Marty.

[johncar]

Hey most recreational boats pretty much have a predesigned top end speed limitation so bigger HP won't necessarilly make it go any faster if it is already at it's max hull speed. What you will get though is better power to weight ratio so when you load her up it will cope much better with a few more horses and you can prop it a little lower therefore giving a lower RPM cruise range and often better fuel economy.
A dealer will often fit the smallest engine that the boat can adequately perform with and rightly so because it will do the job particularly if it is only to be used by a single operator in light trim and it keeps the price tag lower.
For most of us though we fill it full of all sorts of gear and throw in some mates or the Mrs and Kids and then a 4.3m will struggle with a 30HP in most cases.
When I am buying a new boat I generally look at the manufacturers recommended HP range and choose either the max or more often one size down.
So if the HP rating were 30 - 60HP then I would fit a 50HP most likely.
But horses for courses, if I needed to be able to remove the engine, then it would be the smallest one LOL.

And also you can't take too much notice of engine vs boat vs top end and cruise speed, there are just too many variables there in play. You can only do those tests on the same hull, same load, same engines for any definitive results. A colleague of mine did drecently upgrade the engine on his Quinnie not sure of his model but went from 30HP to 40HP and he hasn't stopped smiling and that is because it performs as well now fully loaded than with the old engine with just him on board.
So you just have to work out how you are going to use it at the end of the day and whether you will be happy. Usually a cheaper exercise to get it right the first time.

[Chas & Clarry]

The suspense is killing me....new 4.2 with GPS that will get on the water later this week I hope....can't wait to speed test her :)

[TheSaint]

The suspense is killing me....new 4.2 with GPS that will get on the water later this week I hope....can't wait to speed test her :)


Let us know what it does mate??

[Shawn 66]

The suspense is killing me....new 4.2 with GPS that will get on the water later this week I hope....can't wait to speed test her :)
Tim ,
I think I told you , I can't remember I get 51 KPH with my 40 4 Stroke at WOT . That is with me , all my crap , and the livewell full . You should do better with your 2 Stroke .
Shawn

[Eug]

now that i think of it i should have clarified exactly what bretty blaster said, i will back off a little once on the plane.


I have the same set up and I get 51kph on the GPS.
Marty.
going by your signature you have an open boat, mine is a runabout so i imagine the windshield will create a bit of drag. have you played with props? i'm in the process of putting on a hydrofoil on to improve my holeshot (still not sure if i'll lose any turning stability) and then i hope to play with props to stretch her legs a little more.

[kind_cir]

Thanks for all the good replies. I will be going the 40hp option, and if i can get it to cruise at 22knts -40kmh and wot at 50-60kmh then I'll be very happy indeed. Most of the time it will just be me but sometimes another 1.5 peeps onboard.

[marty+jojo]

now that i think of it i should have clarified exactly what bretty blaster said, i will back off a little once on the plane.


going by your signature you have an open boat, mine is a runabout so i imagine the windshield will create a bit of drag. have you played with props? i'm in the process of putting on a hydrofoil on to improve my holeshot (still not sure if i'll lose any turning stability) and then i hope to play with props to stretch her legs a little more.

Yes Eug, open tinny, running standard prop no hydrofoil.
Marty.

[Giveitacrack]

Spend a few more bucks and get a 3 cyl 2 stroke 40.You wont regret it.

[Richo1]

Clark pursuit 427 with a 40 four stroke merc on the river 1 up got me up to 54km/hr or 30knots. Only had it out twice since new.
Very happy with that! 6days to go before 5weeks off so lots more sea trials to come ;)

[LittleSkipper]

kind_cir...you clearly have no sense of humour therefore I'm inclined to mail you a box of Kleenex to :'( on :P

[Chas & Clarry]

Tim ,
I think I told you , I can't remember I get 51 KPH with my 40 4 Stroke at WOT . That is with me , all my crap , and the livewell full . You should do better with your 2 Stroke .
Shawn

Hey Shawn

The boat is on the water!! I'll post on my own thread with some picies later.

I got exactly the same speed as you ie 51kph with me (82kg) Trace (undisclosed weight ::)) live well full (75kg) and a fair bit of fishing gear. I am happy with that. Will give it a go later with us me on board.

So that is a 4.2 pretty heavy side console estuary boat with a 40 hp 2 stroke Yammy.

VERY HAPPY with the boat ;D

[Seahorse]

Do the permatrim give u less top end speed?
I got 455 seaway, 50hp 4stroke yammy and get top speed of 50 kph by gps.

Cheers
Greg