Will i lose speed going from a 6.5 to a 5.5 pitch prop?

[shiyfire]

Im looking to replace the 6.5 pitch, plastic prop on my 5 hp gamefisher and all the replacements are a 5.5 pitch.Will my motor perform about the same or am i likely to lose or gain any speed?
thanks

 

[blueoval78]

Re: Will i lose speed going from a 6.5 to a 5.5 pitch prop?

I think you may lose a little. I had a 13.5 pitch on my Force 50 and could do 28mph @ 4500 rpm's with my boat. I dropped down to an 11.5 thinking it would put me more in my sweet spot and though I went up to 5000 rpm's, my top speed dropped to 25mph.