15hp to 20hp Carb Kit Upgrade???

Hey guys, the boys and I are buying a bigger river boat and have a question.

Is there a carb kit available for a 2003 Mercury 15hp fourstroke to increase the horsepower?

I saw there is one for 2006 and newer to add 5hp, but curious if it’s possible on an older model?

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Boys have a “need for speed.”

I’d look to see if the 20hp carb or kit had a different part#. It could be a different carb, ignition, flywheel, intake, or a few of those to change the hp.

Dave maze wrote:

I’d look to see if the 20hp carb or kit had a different part#. It could be a different carb, ignition, flywheel, intake, or a few of those to change the hp.

Have to agree to find out if it will I would pull up part specs and see if the 15 has all the same part numbers as the 20 block etc.

I know the 2.5 Optimax`s 135, 150, 175 share pretty much the same things except the 175 has a different block so different porting even thou it is a 2.5 block.

Thanks guys.

I reached out to Iowa boy this morning too, sounds like that motor is maxed out already.

Today I’m picking up a 16′ S model (substantially bigger than my current 14′ C model). I’ll try my 15 horse on it, but I have a feeling by the time I add a bow mount and battery that I might not be able to plane out with the kids.

I’ll report back if it does work though. If it doesn’t, Iowa boy is already offering to sell me a brand new bigger motor

A new 40 hp Suzuki with electric start and power trim on that 16′ would be very nice indeed – they are a lifetime motor, and you can be sure that Iowaboy1 will take care of you.