4.5 slow out of the hole

[warrior]

i have a 4.5 bluefin plate boat and have just put a 60 hp4stroke yammy on it getting it up on the plane is a bit of a push,once up it is great but very slow out of the hole i had a 40hp 2 stroke merc on it with a stailess hydrofoil and didnt have that prob,would it be the height of the motor or need a hydro foil the weight of the boat with all the gear in it is around 700kg to 800kg the motor is brand new so is it also a bit tight ,just runin 7hrs it also has a 12 degree pitch aluminium prop.any advise would be great.

[squizzytaylor]

Im thinking that there is something fishy in your setup warrior, That should practically leap out of the water with a 12pitch prop and have a terminal speed of around 24 knots. Is the boat going bow-high whilst accelerating or does it retain a flat attitude?

Geoff

[lampuki]

Hi Warrior. The fact that the previous donk had a hydrofoil could be a major issue. Placing weight towards the middle/front of the boat will assist to get on the plane. I hope you get some good help from this thread and that it does not degrade into a my engine is better than your enging thread. All the best and i hope u get the solution u need!

[FNQCairns]

I know of a bluefin 4.5 with the same engine, pitch prop, but it's a pressed boat ...is yours really plate? If it is plate how much heavier is it over the pressed versions??

Anyway the boat I know is fine, it does have the typical 4st lack of punch on take off but once spinning it's ok everywhere.

cheers fnq

[warrior]

squizzy yes the boat does go nose up when first starting off ,it does around24knots though now ..

[Angla]

Sounds like it needs the foil to help it jump up on the plane.

Does the new motor have trim and tilt?

Do you have a picture of the motor trimmed fully down (from side on) showing the line of the keel and the fin above the prop

Chris

[Fixation]

Hi Warrior,

My 4.6 quinnie had a 50HP 2stk yammie on the back. I know it wouldn't weight anywhere near the Kg's of your's. Once I put a foil on it totally changed how the boat jumped out of the hole and how it leveled the boat out once planing. I'd recommend it if your thinking you need punch out of the hole for sure.

Regards,
Craig.

[Poseidon]

I have a 60hp Merc 4 Stroke on the back of my Wildcat. The boat is a bit shorter than the 4.5m however the weight would be close.

I initially had problems getting the boat on the plane however lifting the motor up one hole made the world of difference.

Not sure if this helps but it may be worth a try.

Regards Cameron.

[warrior]

angla i will get one for you asap ,fixation i have one and dont really want to driull holes thru the new keel if i can help it i will exhaust all other avanues first before i go to that ,thanks for your help.fnqcairns yes it is a plate they bought them out in 2003 my model was one of the first i think 3mm all round,it would be a lot heavier than pressed as they came with floors and fuel tanks

[STUIE63]

Warrior I had the same boat and motor combo it went great i did fit a permatrim foil to it because we used to have 260kg of calorie enhanced fisherman sitting at the back and no one at the front still came out of the hole allright i think it could be a motor height problem. on my own i didn't need the foil but with two up the back it really helped . I ran the standard alloy prop
Stuie

[boatie_72]

Its still a pressed boat, it just runs with 3mm slab side in place of the 2mm pressed, A true plate boat would run a stringer system not a ribbing system like the pressed boat builders ie. blue fin, quintrex, ally craft, horizon, sea jay etc. Most brands now have the 3mm as a option to there models.

I would check engine heights, and trim angles, they play a major part on the way the boat will proform. Is the boat still slow onto the plane if there is someone up the front???

Cheers

[Dan5]

Mate i have the 4.5 warrior with a 60 yam 4strk,it's a little slow "out of the hole" but not that slow.It's running a 11 1/8 13-g prop and i'm getting around 31.5 kts loaded with 2 up.

Cruise speed is around 24kts,my engine would have done roughly 80hrs by now.

[Blaster Bretty]

2 strokes are said to get the power down a lot quicker than a 4 stroke of the same power rating, you said that your boat, once on the plane, goes really well, it could be you just have to get used to the power delivery of a 4 banger, it would seem strange to have a different cav plate height on the new motor but im guessing that a 60hp 4st would be way heavier than a 40hp 2 st, this too could be whats up.

Bretty

[warrior]

boatie72 yes it still labours a bit with someone up front the hole setup is one down from where the 2 stroke was i will get it lifted on the first service then see how it goes,thanks everyone for all your input it has helped heaps on ideas how to fix the prob

[squizzytaylor]

Warrior, you may wish to consider smart tabs, these will keep the nose down and help the boat onto the plane considserably quicker. No messing with the outboard, take about 20 minutes to fit.
I have had them on a smaller tinnie and the difference was oustanding, I have heard similar stories from many others too.
http://www.samallen.com.au/Smart%20Tabs.pdf

Geoff

[Rob128]

Hey Warrior,

I have a Quintrex 460 with a Yamaha 60 (4 Str).

The boat & motor weights approx 590 Kg. If I have the engine fully trimmed down it hops on the plane 'ok' and once on it accelerates away very quickly.

I changed props from an 11 5/8 x 11 to a 11 3/8 x 12 mainly because at WOT i'd see 6100 RPM. I noted that the mid range and top end really benefited, although the botom end is a little more 'sluggish'. For me when were fishing this is no probs as fuel economy is even further improved.

We do a bit of tubing now and i've really noticed the accerelation from a standing start just isn't there. I will go back to the 11 5/8 x 11 for tubing and put the 11 3/8 x 12 for fishing and cruising around.

One thing I did notice just recently is if I have the motor trimmed a bit too much up (sorry for the bad nautical terminology) then the boat is even more sluggish until its gets on the plane and its business as usual.

I have played with my trim setting, one bar at a time, and found that the best trim position is only two bars from full down. Could it be that your motor does not have enough down trim angle ie: angle of your transom, etc.

Hope it helps.

Regards,

Rob

[BARRA73]

Mate I have a Bluefin Wildcat which should be around the same weight with a 60hp e-tec and I'm not trying to start a 2stroke vs a 4 stroke argument but I couldn't be happier with holeshot acceleration and overall speed. I'm not quite sure what size prop they come with but it's a viper i think.

[UNCLE NUGGY]

gday warrior
i was wondering if the 700-800kgs was with skipper & crew ,or just naked boat with all gear. sounds heavy to me for the hp.
cheers
UN

[warrior]

uncle that is with all the gear ,full tank and 2 people

[warrior]

angla here is the pic of the motor trimmed down do you think it is too low

[Jono_SS]

I don't know a huge amount about this sort of stuff, but I'd be thinking 24 knots is a pretty low top end speed for a boat that size with a 60hp donk. i realise a lot has to do with hull shape rather than hp, but when Dan5 says he can get 31 knots out of the same setup, I'd be a little concerned with yours.

I used to get 28 knots out of a very similar boat (stessco tornado) with a 50hp tohatsu, even though it could be sometimes hard to get out of the hole if it was full of people, fish, ice and water.

a foil will almost definitely help get it out of the hole, but I'd be trying a few other things first (like talking to the place you bought it from), as you will lose a little more top end speed.

[Blaster Bretty]

to me that pic of your motor trimmed right down like that looks way too far in and needs to be a bit more flatter at the point of lowest trim. you could trim it out a bit to help things a little,have the cav plate in a straight line with the bottom of the boat.
Hope this help's, can someone correct me please so I know im on the right track??

Bretty

[Angla]

I think a few should confirm this...

The motor is too low. Try lifting it one hole first and see if there is a difference.
I think it could probably come up 2 holes.

The angle of the motor trimmed in should be right as it will keeps the bow of the boat down as the water forces the cavitation plate upwards.

In the first pic, it shows the keel line (timber is being held along the keel) when the motor is trimmed in.

The second photo shows the keel line (timber is being held along the keel) when the motor is trimmed horizontal to the keel. Note that the keel line is approximately 25mm under the cavitation plate. ie the cavitation plate is higher than the keel.

When travelling at a planing speed you should see that the cavitation plate is above the water because it would cause drag if it was still under water.

Hope this helps

Chris

[robbo51]

Some useful stuff here for me too....in the process of setting up new rig...same motor on 485 Horizon Getaway....went from 13p back to 12p with some improvement...now revs to 5800, was only 5200...similar top end around 27kts, but planes a bit earlier. Currently one hole from top

[Angla]

Does anyone else think it is a motor height problem?

Chris

[Kleyny]

I would say take it up one hole and see how it goes then.
How much weight does it have in the back? the more weight in the back the harder it will be to get it on the plane.

It would only take you roughly 1hr to raise the motor yourself.
Put a block of wood under the skeg undo all the bolts bar 1. run some rope around the motor so it holds against the stern. then undo the last bolt. get someone to find the jocky wheel up until the next holes lione up with the stern holes.
Put the bolts back in and your done.

I have a thread on this site in regards to my motor height so try doing a search for it.
I do agree that you should just be able to see your cav plate but every baot/hull is different,
I cannt see mine but when i went up to the next hole it cavitated way to much.
Are you triming it right under on take off then trimimg to set the cruise?

neil

[warrior]

honky i have had the motor on for only 2 weeks and it has done only 7hrs still sussing out the trim level which power to use to get it up and going i have the console back further than normal towards the back and there is 2 batteries but thats all.

[Kleyny]

If thats all you have at the back it shouldnt be a drama.
I always have my motor trimed all the way in and most of the time flat to the floor for take off then once its up then play with the settings.
I just have to make sure everyone is ready before i give it to it as i almost made my wife go for a swim. (not happy).
By the way i have a 4.6 quinny with a fare bit of extra weight with a 2st 60hp 13" pitch merc and it shoots out of the hole and does 60km/h by gps wether its loaded or empty. it weighs roughly 600 empty and half a tank of fuel

neil