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Eddles

Whats worn and needs to be replaced

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#1
Howzit all, need a little guidance before heading off to the Boat shop, don't want to get ripped.

I recently bought a 440 in really good nick but seems to have a few things that might need replacing now that I have had it out on the water. Please could I have some advice on your thoughts.

When opening up the trhottle to get on the plane I get burst of heavy vibration comming through, also seems a little slow to get on the plane, not sure what I should be comparing it too Smile need to play with the throttle to get it on properly, once it is on the plane it runs fine but has a bit of vibration, shakes Lowrance on the Ram mount. not sure what could be causing thsi vibration?

Motor needs to be trimmed almost all the way down to keep a smooth plane, I see the motor is mounted very high but has a metal wedge inbetween the transom and the motor, not sure if I should remove this and maybe drop the motor a notch. As at WOT the prop feels as though it looses a little grip.

Feels like there is also a lot of play on the Safe T steering system, not sure how much play there should be but wheel moves about 2 - 3 cms before motr moves.
Battle to keep the boast in a straight line at low speeds.

Think the best I saw was 55kmph at about a touch over 5000 rpm

Other than that the boat runs really well just the vibration and steering that I am a little concerend about.

Rebel 440
Merc 75Hp 2 Stroke
13.25 x 17P prop (Looks like it migh have been repaired as it looks new but has a rough edge on one plade.)

Any ideas?

Cheers
Wiki
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BWG
#2
The vibration is probably caused by the prop - its likely that when it was repaired one of the blades was not set properly and is out of alignment. Start with another prop.

Don't quite know what the 'wedge' is that you are talking about but that could be one of the reasons why you struggle to get on the plane - the motor needs to be trimmed all the way in to assist with hole shot and planing.

Push-Pull steering will have a bit of play but perhaps you will just have to tighten the cables a little to reduce the place.
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#3
Thanks for the advice! The wedge definetely pushes the motor to more of a trim angle.
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#4
Hi Wiki

Warning:
I had to redo my buoyancy on my 440 as it wasn’t up to par i.e. it sunk like a rock!!

Have your steering cable checked to see if it complies with the motor specs… Had to replace mine when it snapped at high speed.

The vibration is definitely to do with your motor or prop.

When your on the plane and running at 5000 rpm trim the engine up “ rooster tail” the boat will stop bouncing and you should reach top speed.

Going at 5000rpm with your engine trimmed down will put a lot of stress on the motor.

Extremely happy with my 440 Sport after all the above was sorted!

Cheers
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#5
Thanks for the advice Juba, sounds like I am trimming my boat completely wrong eish! I normally start all the way down and then when the bow starts to drop I only trim up a little. If I trim up more it feels like we are about to start bull riding. I then trim a little down again and off we go. So what you are saying is we need to break through the bull?

I will also check the bouyancy, have foam and it seems dry.
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#6
Youll have to play with it... Ive got a 90 on
Will be diff I suppose ..

Lol! Yes, ride the bull !
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BWG
#7
Morning Wiki. Some good advice given.
You should have no problem getting on the plane quickly with a 17" prop and that gear ratio for that motor. In fact, the motor might be capable of over revving at WOT...........??
Put a spirit level on the boat deck and get it level with the jockey wheel, then do the same with the motor by putting the spirit on the cavitation plate of the motor.
NOW, at what level is the cavitation plate in relation to the bottom of the keel of the boat at the back? Are you running a 3 or 4 blade prop.
[Image: big_fish_eat_little_fish.jpg]
BIG FISH EAT LITTLE FISH....
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#8
Hi Riprap, thanks for the reply, motor is running high, think the previous owner set it to the max, just popped outside to take a pic, then you guys can see the setting and wedge. The cavitation plate definetely sits at almost max
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#9
Morning Wiki. I don't fully understand transom angles myself but the wedge is there to bring this angle into an accepted norm. Maybe the boat fundis can enlighten.

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Click on the pic to view a larger and full version.

This is what I was getting at. Get boat and motor level and check this. The starting rule of thumb for a 3 blade prop is level and for a 4 blade prop an inch or two higher.
Your motor is already set at max??
It's easy to set yourself. Place the motor skeg on a piece of timber and loosen the bolts. You need 2 people. One on the jockey wheel and one holding the motor and placing the bolts.
Load your boat for normal fishing and test various settings until you find the right combination.
[Image: big_fish_eat_little_fish.jpg]
BIG FISH EAT LITTLE FISH....
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#10
I agree with Rip, check the heights before you do any motor height adjustments

Wedge - toss it away. The boat was never manufactured for a wedge. Simple as that. First remove wedge, test again, then decide if you must adjust engine height.I'd got his route first before fiddling with the motor

BUT, I must caution you against lifting/changing motor heights to be easy...

I would suggest you get a car mechanic buddy to help you. Ask him to bring his engine hoist/hydraulic lift with. Pop a ring bolt into the top of the fly wheel (the round thingy on top of the engine when you take the motor cover off), then take up the weight with the engine hoist/hydraulic lift. Remove engine nuts and adjust accordingly.
Note, you might have to remove the fuel tank if it is built in. This will allow you to get to the head of the bolts on the transom to tighten/loosen. Also, this will allow you to reseal the bolts with silicone. Don't forget to put a silicone sealant on the motor plate before re-mounting to the transom.

Get that prop re-balanced too. It could be the root cause of the vibrations.
Question: Is it vibrating severely on pull away or at the higher speeds? If the former then its unbalanced, if at top end then I'd say its the wrong pitch - which makes you think its loosing grip i.e. cavitating

Lastly: where are you based? I'm sure someone from the community will be able to pop past you and have a look see with a different set of eyes.
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#11
Thanks for all the feedback guys! Really good stuff. I have been pondering over that wedge, didn't really know what it was for but tossing it was always on my mind. Will get the wedge off, check the height and maybe adjust by one or two positions lower. Main prop shudder comes at low speed before coming onto the plane, prop was definetely repaired as after this weekend out the paint is startinbg to come off and I can see the dimples on the suspect blade, also looks to be a little egged at the exhaust end, will replace prop and keep this one as spare. I am down i Nelspruit, not sure if any members around these parts? Now for the pitch question, the one boat shop I checked in with said I should go with a higher pitch, maybe 21.... now I have no clue lol
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BWG
#12
The ideal pitch would be one that gives good hole shot (fully loaded), a reasonable speed and which doesn't exceed the engines recommended max rpm @ WOT.
Thus, tell the oke who wants to sell you one you would like to test a 17, 19 & 21" so you can see what suits your configuration. Stainless is always better of course so don't rule out Solas in CT once you've made up your mind.

<!-- m --><a class="postlink" href="http://solas.com/newweb/propeller/where/africa.asp?AC=&AName=&Cno=5&CName=South%20Africa" onclick="window.open(this.href);return false;">http://solas.com/newweb/propeller/where ... h%20Africa</a><!-- m -->
[Image: big_fish_eat_little_fish.jpg]
BIG FISH EAT LITTLE FISH....
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#13
Thanks for all the advice guys! Just out of interest what Max speed should I be aiming for with my setup without sacrificing holeshot
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#14
I would aim for not exceeding max 5500 rpm on that motor. With that hull and motor my gut feel is 55 - 65km/h would be reasonable. Doubt you will get more without sacrificing some performance issues elsewhere.
[Image: big_fish_eat_little_fish.jpg]
BIG FISH EAT LITTLE FISH....
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#15
55 sounds obtainable so lets aim for that, I think anything above will start sacrificing other areas! Let's get started lol now to find a hoist!
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