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Old 10 May 2006, 11:42   #1
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50 HP + 5HP Auxiliary would it be to heavy on a sr 4 ?

Can you help

I’ve been offered a 5hp Yamaha as an auxiliary for my SR 4
If there’s room, would it be too much weight on the stern/transom for the balance of the boat with the 50hp Tohatsu?

The 5 hp is from the 1980's but is as new and foc
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Old 10 May 2006, 15:13   #2
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Whats the total weight.

I'm carrying about 115 Kgs with a Yam 4 stroke High Thrust. I use to worry about the weight on the back but its never been a problem. Obviously lighter is better but you can't have all things.

I have had no problems with transom flexing, nor water pouring over the back when you slow down. It takes a bit of getting used to when your punching sharp waves and the boat is spending a lot of time at 45 degrees. But the boat handles it well. As a test you could always put some ballast at the rear of the boat with your present setup and see what you think of it. Try putting a person there.

The only thing that would concern me is that I would have to remove my A Frame and would a 5 HP motor actually push you anywhere. I wouldn't think so if you let the hull fill with water and it was even slightly rough.

If you manage it let us know. Nos4r2 had something similar. It would be good to hear how the setup ran in anger, as such.
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Old 10 May 2006, 16:27   #3
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Thanks

Tohatsu is 88 kg and the Yamaha is 20 kg so that sounds ok, I’m looking to fit an A-frame to, so will have to see if I can get over that.

Where is your fuel tank and what is its capacity as this would surely also have an impact?
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Old 10 May 2006, 19:29   #4
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I've got a 4hp aux and a 50 on mine at the moment.
The only way I could get it to fit was to trim down the 4hp johnson's clamp. I don't have a huge amount of steering throw either (original SR4 teleflex) and the two cowls only miss each other by 5mm. It's workable but only just.

I still have my a-frame fitted but I wouldn't want the aux any closer to the toobs either.

4hp as an aux is adequate... about 4-5 knots. I doubt you'll get a 5 to fit.


My tanks are inside and in front of the console and total 80 litres so around 80kg-but being that far forward they help balance the boat quite well.
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Old 10 May 2006, 21:50   #5
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cant really comment as my trim tabs would be in the way, all sound advice from the boys above tho hope u find a good resolution
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Old 11 May 2006, 12:46   #6
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With regards fuel on my setup I carry a 25 Litre tank in the bow. Fifteen litres under the seat and anymore I might be carrying will be in 5 litre cans thrown up front. I need to keep everything up front to balance it out a bit.

With my own experience I don't think you'll have any problems with your setup with regards weight. I do notice a difference in the handling compared to my mates boat with only a Yam 40 HP 2 stroke on the back. That seems to be the best setup. His boat flys across the waves much better than mine. Might be because he doesn't get scared like me.

The time I really notice a difference is if I am carrying second adult and they are standing up in the rear.
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