On my new yamaha 40 hp two stroke there was a power tech stainless propellar

on it when i bought it.I wrote the numbers down went to there site and it said i

had a 10.38" diameter prop with a 13" pitch in satin finish with cup.Question is

how do i know if this is the proper prop for my boat setup,i do not have a tach. :-/

You don't.  RPM is your main indicator for telling if you have the proper prop.

Please read http://home.comcast.net/~team_dougherty/fishingtips.html tip #4

Same prop I have on a Triton 17' with a 50hp Mercury 2stroke...gonna guess your pretty close on prop, if your off your not far off.

Good info above on props and rpm's.

If i had to guess i think i'll be running in it's upper range of rpms 4500-5500

with my setup,the boat is only 550lbs,add 189 for motor,110 for two agm

batteries and 50lbs for 6 gallons gas,then two people.

You can see it at www.weld-craft.com/SpecialtyBoats.htm

Good info above on props and rpm's.

If i had to guess i think i'll be running in it's upper range of rpms 4500-5500

with my setup,the boat is only 550lbs,add 189 for motor,110 for two agm

batteries and 50lbs for 6 gallons gas,then two people.

You can see it at www.weld-craft.com/SpecialtyBoats.htm

You should get a tach and find out for sure. There can be a 5 MPH between 4500 and 5500 RPM with a 13" prop