Yamaha hp upgrade.....

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mattswan2512
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Yamaha hp upgrade.....

Post by mattswan2512 » 08 Aug 2017, 13:31

Hi all,

Spoke with somebody today who works with outboards and he told me that its very simple to upgrade a 10hp yamaha to a 15hp by simply upgrading the reed block? All carbs are the same etc and this is all you need to do.

Can anybody confirm or quash this? I know they share power heads but id of thought their would be more to it than that......
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Paul B
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Re: Yamaha hp upgrade.....

Post by Paul B » 08 Aug 2017, 16:34

Not sure on the Yamaha. But my Suzuki df9.9 was a simple carb swap to get it to a 15, I think Andy B has done the conversion on something else, and I'm sure I've seen something before on swapping the reed block but cannot be sure
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Andy B
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Re: Yamaha hp upgrade.....

Post by Andy B » 08 Aug 2017, 20:48

Yep,
Yammy 9.9 2 strokes are simple :D
Pre 1995 OB's have a 4 petal reed block, these need to be replaces with a 15hp reed block (6 petal)
Post 1995 OB's already have a 6 petal reed block.
In this case you can either replace this with a 15hp reed block or simply open out the reed stops to 25mm gap between them.

Also check that the carb butterfly is opening fully to the horizontal position. Make sure the engine is in gear (not running! Obviously ;-) )
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mattswan2512
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Re: Yamaha hp upgrade.....

Post by mattswan2512 » 09 Aug 2017, 08:01

Happy days thanks andy. Glad it is as simple as he said.
Life is like a chocolate bar........
If you hold onto it for too long u get covered in sh☆t so......
live a life you will remember, not a life full of untested dreams.

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