Would trying a four blade prop help? They provide a lot more grip on the water.
Would trying a four blade prop help? They provide a lot more grip on the water.
Darren
Yes it will. But will still require some additional cupping.Originally Posted by Darren Mc
Are you saying you think it has gone from a short shaft to a long shaft? Or the other way round? Bit hard to follow. What did the dealer say about the new vs old motor height when purchasing ?
Was the 4800 at WOT, i.e. flat stick? If so, and you do have a 13" on it at present, forget the 15" - complete waste of time. Find/read the numbers on the existing prop first. Might have to take it off to find the numbers.
Where was the motor trimmed at this point?
Did the dealer who fitted the motor test it?
Forget tabs, foils and whatever for the time being, sort/confirm the prop and height/shaft lengths first.
Cheers
i've been reading up websters, they all recommend long shaft, wasnt sure if the one i got installed was one
motor trimmed is middle according to the gauge
they said they tested it, but i always like to get a personally testing
5knots @ 2200 in trolling mode
20knots @ 4800 in 10k knot wind that was plane
27knots @ 6000 in 10k knot wind that was WOT
what im worried about is how the water flood the mounting bracket of the outboard or pretty much where cover seals is, as seen in the video... before it takes off... i know that not normal... trying to fix that problem =/
but wind been so bad cant do anything until it clams down hopefully this wk or so
Hello Mitc69,
I have a Webster 4.3 and your photos look very familiar to me.
Straight up the motor is too low.
Your cavitation plate is below the splitter that diverts the water away from the leg.
You have a long shaft motor, that is 20 inches a short shaft is 15 inches which is far too short and I doubt that 70hp Suzukis come in a short shaft.
Attachment 112086
Measure the height as per the vertical red stripe, it will be 20 inches or about 500mm.
If you lift the motor to the top hole it will be a lot less affected by the water.
I am talking from experience here, my motor sits in the top hole and operates perfectly.
The performance that you show is about right, I have a 60hp two stroke and I get 18 knots at 4000rpm, flat out 27 knots at 5500rpm, by GPS.
I watched your video and I don't see a problem, that wash is normal.
No need for custom cupped propellors ask any Webster owner, the engine setup is no more difficult than any other boat.
This talk about aerated water etc. in the tunnel is incorrect, mine operates perfectly with slippage or aeration, except when she jumps out of the water!
I would be having a good chat with dealer concerning the setup.
Ooops,
Should have said without slippage or aeration.
The four stroke may be heavier than the previous motor and the small cats a sensitive to weight on the transom.
Before you fit a foil, check that it does not void the warranty, Yamaha will void if you fit a foil, I don't know what the Suzuki policy is.
I have transom wedges that offer the same result as a foil without warranty issues.
I know because I have used two Yamahas, one with a foil and one with wedges and they both provide the same low-speed planning and trimming performance.
Keep us informed how you get on.
Hello mitc69,
I have just checked the Suzuki website and the 70's only come in 20' and 25' versions, no short shaft.
At 155kgs it is a very heavy motor for a 70hp, you may well need a foil or transom wedges or carry extra beer under the foredeck.
http://suzukimarine.com.au/outboards.../product/df70a
hey croc
is the 4.3 webster fuel tank in the back too? im planing to move the fuel tank to the near font?
yeh gonna give it more testing when wind clam down, sadly cant talk to the dealer there in townsville =/
Mate, Dont move the tank, The motor is to low, It needs to come up atleast a hole maybe 2. once you have done this then play with the props. seen pleantly of these boats fitted with 70hp Yamaha 4 strokes.
yup gonna taken into suzuki cleveland tomorrow and move it up 2 holes and see how it go
Hello Mitc69,
any progress?
Mitch once you have the height set right I would be adding a foil (or even before). The fuel tank in the rear like that is making the boat ass heavy and ay 155kg the engine is also adding to it. I went through the same process after I fitted a 65L fuel tank to the rear of my 4.3m CC. It launches onto the plane very fast now. Once that is done you can find the right prop though the one you have looks good pre foil.
If the boat is going to be used in the open ocean a lot trim tabs would be beneficial for sure.
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