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Old 02 June 2008, 09:16   #1
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Auxilary Engine....

What size auxilary should I get for a 7.5m? I've been told a 15hp but that seems a bit extreme and indeed heavy to me.
What do other people have?
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Old 02 June 2008, 09:55   #2
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I thought the general rule of thumb for an aux was 1hp per metre of hull?
I may be wrong though!
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Old 02 June 2008, 10:04   #3
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Get a 2 stroke if you can - much lighter.

It all depends what conditions you find yourself in - if you are a long way offshore fighting headwinds and tides then yes you need one. On a flat calm day a 5hp would be great.
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Old 02 June 2008, 14:46   #4
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I think most auxilarys are to small to be able to cope with the boat in anything but flat calm, so I don't carry one but I keep spare parts for the motor and keep it well serviced and fuel very clean. And a good anchor with loads of warp.
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Old 02 June 2008, 15:30   #5
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Thatsu do a 9.8hp 2-stroke which weighs only 26kg. Even better is the same engine in the Sail Drive range. Although they are no longer imported (EU emission regs I believe) I think there maybe still some around. Well worth the search for a lightweight. reliable and relatively cheap solution.
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Old 03 June 2008, 00:21   #6
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Quote:
Originally Posted by BobLS View Post
What size auxilary should I get for a 7.5m? I've been told a 15hp but that seems a bit extreme and indeed heavy to me.
What do other people have?
I've got a 15HP 2st on a 6.5 m and would not go any smaller, if you want to go smaller and lighter a pair of oars
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Old 03 June 2008, 02:40   #7
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Get some friends to boat with. Tow lines are cheap.
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Old 03 June 2008, 05:04   #8
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Quote:
Originally Posted by BobLS View Post
What size auxilary should I get for a 7.5m? I've been told a 15hp but that seems a bit extreme and indeed heavy to me.
What do other people have?
As noted, the Tohatsu 9.8 two stroke is ideal but hard to find.

Anything smaller than around 10HP is going to be more of a maneuvering thruster than an auxiliary drive, the bare minimum would be a 5HP in my opinion.

In any event having a good anchor and some basic spares is always a good plan.

For info, the four stroke Tohatsu 9.8 is the same weight as the 8 = 39kg

http://shop.malthouse-marine.com/ind...d=15&parent=20

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Old 03 June 2008, 05:11   #9
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Agree with Malthouse, we have 10 hp on 6.5m. Looking at an older Mariner Catalogue for 2 strokes, the 6hp weighs 31 kgs and the 15 hp weighs 32 kgs. So if your looking at good quality second hand 2 stroke then something between 9.9 and 15 would do nicely. Note there is a difference in cc, 210cc between 6 - 9.9 hp and 262cc 10 hp and above but don't think it's is going to make much difference to you. More important is to get the right shaft length to get the prop down low.

Pete
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Old 03 June 2008, 09:03   #10
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Great - useful tips. Thanks all.
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