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Old 21 November 2012, 08:56   #11
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Country: UK - England
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Hello 9D280.
Thank you for the welcome.

The outboard is on a 5.35 metre SIB. I will have a trawl through the site to see what information I can glean.

The boat is mainly used for fishing with 4 persons on board plus fishing tackle and all the usual boat equipment the approximate weight of "everything" including the boat is 750kg.

The outboard seems to be propped correctly and goes ok through all the rev range. I just thought that if there was an easy way to get hold of an extra 5hp then I might just do it this winter.

Best regards.
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Old 21 November 2012, 11:12   #12
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Boat name: Nautile
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Engine: Tohatsu 18 /30 HP
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The conversion is a cheap piece of cake with wipped cream, extra 5 HP which is at the end of throttle grip will give better hole shot when more loaded and slight final top end speed. Depending on the Letter/Number next to 25, could find the following :

25 HP with restricted carb gasket and restricted time advance to 20
25 HP with restricted carb gasket and no restricted TA to 25

Second is faster to convert as is already timed to 25, just swap carb gaskets for the 30 model.

Happy Boating
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Old 21 November 2012, 16:11   #13
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Hello Locozodiac.
My Tohatsu is a MFS 25B EFI Four Stroke. I thought that the modification that you have posted was for the 2 Stroke models. Unless both Four Stroke and 2 Stroke models have the same modification to increase the BHP to 30HP.

I hope that they do.
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Old 22 November 2012, 10:01   #14
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Quote:
Originally Posted by J_HOU View Post
Hope they do.
Sorry, NOPE, it's only for 2 strokes. 4 strokes 25 & 30 models functions with different CPU parameters. If being same CPU will need factory tech data to reprogram, if not, a complete CPU swap from 25 HP 30 model is mandatory, and it's expensive. 4 strokes engines have an electronic advance system, not mechanical as found in 2 strokes.

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Old 22 November 2012, 10:17   #15
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Hello Locozodiac.
Thank you for the fast reply. Yep, it looks like I will not be doing the 30hp modification this winter.

I might just fit some fins to to the outboard, or, speak to some people I have worked with in the past who reprogram EMU's for 4 Stroke engines. The problem with re-mapping the EMU is that I cannot use a rolling road.

I think that it is too much work for an extra 5hp though.

Best regards.

Best regards.
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