99 Johnson 50hp [upgrade??]

I have a 99 50hp Johnson on the back of a 19' boat. It will run the boat at ~ 24mph but it does not have enough power to lift the bow if someone walks up the the front of the boat. the boat is rated for a 150hp but I don't have the cash to remotor right now.

If I remember correctly the 2 cycle 50hp is the same bore/stroke as some bigger motors. Can I bump up the hp by changing carbs?? or is there more involved?

Any thoughts on the good and bad of doing this?

 

IIRC, the 1992 to 2004 Johnson 50, 60 and 70 did share some common parts; I don't know for sure if the blocks themselves are identical.
You'd need a good shop manual for that motor to perform any such surgery on it, if it's possible. The carb will probably be the biggest difference but there will likely be a few other things that have to change... all in all, I doubt you'd end up cheaper than just selling this one and buying a used 70 of similar vintage.

 

The 15 hp '99 model Johnson I have as a spare on my Lund has the same block as a 9.9 hp, but the 9.9 has a smaller bore and smaller carb. I assume the same is true of the 50-70 series. You must have a heavy boat, I used to have a 50hp Honda on a 20 foot alum flat bottom with 7 foot beam and it would go over 40mph with a pretty good load. your boat is rated for 150 for a reason, I would start looking on Ebay for something over a hundred HP, boring your engine out wont do that much for your problem.