Converting a Gamefisher 9.9 to a 15hp?

[vahunter]

a few of the lakes near me have a <10hp rule. I have a Gamefisher 9.9hp (Model number 225.581994) and i want to make it run like a 15hp. I see there is difference in the carbs but i was wondering if anyone had done this to these motors and what they could tell me about it. Ofcoarse i can spend 8hrs comparing part numbers but i figured someone has done it. Thanks,

Buddy

 

[truckintyler]

Re: Converting a Gamefisher 9.9 to a 15hp?

I think these engines were made by force/mercury or force/crysler I'm not quite sure but someone in that forum might help you.

 

[Jeremy T]

Re: Converting a Gamefisher 9.9 to a 15hp?

I haven't done it but i have researched it alot. From what i have read on another forum on this site that all you would need for your engine is a 15 hp carb. Your 9.9 is just a detuned 15hp they do this for sales reasons because of the 10 hp rule you had spoke of. If i was you and had a 9.9 i would buy a rebuild kit that comes with everything for a 15 hp and install it on the 9.9.

 

[vahunter]

Re: Converting a Gamefisher 9.9 to a 15hp?

So a rebuild kit for a similar year 15hp will 'convert' a 9.9hp carb?

 

[steelespike]

Re: Converting a Gamefisher 9.9 to a 15hp?

In all the years I've been on here I don't think anyone has asked about how or said they had done it. I do know that motors after 84 are 15.41 cu in. 9.9 before 85 are 13.15 cu in. compression
on 9.9 before 85 is 115-125 after 84 compression is 125-135.

 

[vahunter]

Re: Converting a Gamefisher 9.9 to a 15hp?

comparing the carb components of my 1991 Gamefisher (Force) 9.9 and a 1991 GF 15, there are some differences, more than just jets or a rebuilt kit would change it. Looks like i would be better off with a 15hp carb if that is the only difference with the motor.

 

[fishrdan]

Re: Converting a Gamefisher 9.9 to a 15hp?

Just a carb swap isn't going to do it. The 15HP has different exhaust components, cover plate and tuned exhaust from what I remember. Your best bet would be to find a junker 15HP and steal the parts off it.