Tohatsu 9.9D2 after wrong modification?

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Szmaja

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Good morning dear forum. I will be grateful for dispelling my doubts.

I bought a Tohatsu 9.9D2 from 2002, with throttle cam 362-63718-0 installed. Thanks from reading the forum I already know that this is the wrong cam version for this engine (the correct one is 3M3-63718-0). Nevertheless, the engine is running perfectly fine: it has power, starts up quickly and burns normal amounts of fuel.

Timimg was set at 25 °
The butterfly could fly in 180 ° ...

Please confirm or correct me if Im wrong, whether this modification needs to be fixed?

Engine will work better with newer cam 3M3-63718-0?
 

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pvanv

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3M3637180M is the 15/18 throttle cam, so you got a free upgrade.
 

Szmaja

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Good morning, sorry for my language above I try to write that my Tohatsu 9.9D2 has throttle cam nr 362-63718-0 installed (You can see it on attached photo).

This modification was made corectly?

Thank You for help.
 

pvanv

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Apparently. Many upgrade the old 9.9s to 15s by installing that cam.
 

Szmaja

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Interesting, what is a difrence when they work. The shape in midle range of 362-63718-0 this steep profile indicates that the engine can pick up speed faster. It could give more dynamic haracteristic in midle range. Thanks for help. Best regards,
 

MattFL

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I would guess the original cam probably doesn't open the carburetor all the way.
 

Szmaja

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I wonder what is a difrence without cams: 3M3-63718-0M and 362-63718-0. Can they give different characteristics during acceleration?
 

pvanv

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The 3M3 is also used with the bigger carb to get 18 hp.
 

Argypa

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Does anyone knows the correct position for the timing and if it is easy a photo of the timing.
 
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