Can I increase the HP on my 96' Johnson to 15 without much fuss?

[Seaclusion1]

I just bought a 96' 9.9 from a friend who said that it has the same block as the 15 and can be modified or upgraded simply by changing out the reed valve or assembly? Is there anyone who has experince with this?
thanks

 

[sterndrive tech]

Re: Can I increase the HP on my 96' Johnson to 15 without much fuss?

in the first place,, alot of these motors are put on boats that are rated for more power, so, if you put a 10 hp on a boat rated for a 50 hp, you only get 20% of the benefit of that power, so if you turn a 10 into a 15, uo only gain 20% of the 5 hp
reeds do nothing, you would have to change your carbuerator, but that only gives you about 3 hp extra, you have to pull the power head and replace the exhaust tube, as it is a different length and diameter, my advice, is that you will barely notice a difference, unless you are running it on a very small boat, the cost for you to do this will exceed 400 as the carbuerator alone is over 200. dollars, you can probably sell that motor and with the money you save not trying to convert it, actually buy a 15. a 2000 model 20 hp can be bought for roughly 1500-1800 a 15 hp, 800-1200

 

[the machinist]

Re: Can I increase the HP on my 96' Johnson to 15 without much fuss?

On that late a motor the reed valve spacers & exhaust tube are already the same as used on the 15hp.

Depending on the boat you are putting it on & how heavy you are laoding it down whether you will see much gain in speed. If your boat is just shy of getting on a plane, then a different (15hp) carb may just be enough to get you there. But you may also be able to up your output by simply changing props.

 

[Will Bark]

Re: Can I increase the HP on my 96' Johnson to 15 without much fuss?

I have a friend who did get his HP up by simply buying a 15HP carb off e-bay I think and the performance he was looking for on his 14' aluminium flat. This is a 94 Johnson.