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Old 23 September 2012, 14:23   #1
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Country: UK - Scotland
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Am I on plane???

Apologies for a basic query but..
My baby Merc 6hp gets the bow of the sunsport 3.2 out of the water at 1/4 throttle. Then at about 3/4 throttle the bow wants to bite back into the water. Is this the boat on plane??? My instinct is to throttle back a bit so the bow rises again.


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Old 23 September 2012, 14:42   #2
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Sounds like you might be trimmed in a bit far, or have too much weight up front. Or need a bit more power.

When you hit the throttle, the bow will rise, the boat will accellerate, and at some point, the stern will ride up the slope of water under the hull and climb up on top, rather than push through. That is on plane; the bow should remain up a bit, and the whole boat should be skipping along on top of the waters surface.

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Old 23 September 2012, 14:50   #3
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Thanks jky

There is a pin on the engine bracket that can be moved so should I move this out to increase the angle between the transom and the prop??

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Old 23 September 2012, 15:00   #4
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The boat will have to climb over the "hump", the bow will rise and as you go over the hump the bow will drop again.
Once on the plane you will be able to reduce the throttle and and stay on the plane.

Not sure if a 6hp will get a 3.2 on the plane?
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Old 23 September 2012, 15:07   #5
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My 6hp Mariner would get my Zodiac 2.85m SIB on the plane with no effort at all, achieving 14-15mph on the GPS.
With two of us on board it would still plane fairly easily, if my wife sat at the front to get it going. It still did 14-15mph with two on board.
With three on board it would not plane.
So a 6hp should from my experience plane easily on a small boat such as a 3.2m with only one person on board.
But you may need to get your weight forward on the boat to get it over the "hump" or "out of the hole"
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Old 23 September 2012, 15:07   #6
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Thanks Chewy

I'm managing 17mph with the 6 and given the difference in how the boat handles between 1/4 and full throttle I think that somewhere in there, there is the chance of planing. On searching through the forum it seems that there are plenty of other small engine users who are getting the plane effect but as a novice I'm not sure what this looks or feels like.

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Old 23 September 2012, 15:12   #7
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Thanks Lightning

Yes I think maybe what I'm feeling is the boat planing. If, as you say the bow drops again when it's planing, then that is when I feel like throttling back but actually when I should be getting the big boy pants on and keeping the throttle open.

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Old 23 September 2012, 15:59   #8
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If you are doing 17mph with a 6hp,you are planing..................
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Old 23 September 2012, 16:10   #9
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Cheers Boatnomad

But without having experienced the effect before it's difficult to know. I'll take your word for it. So just to be clear -is planing bow up looking at the sky or bow down waiting for the boat to plough into the sea?

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Old 23 September 2012, 16:19   #10
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https://www.google.ie/search?q=plani...w=1600&bih=744

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