prop for 70 horse johnson

[diana25]

i dropped a prop on my 70 horse johnson and am looking for the best prop for speed. the boat is a 77 glastron tri hull. thanks for any information you can give me.

 

[blueboat1]

Re: prop for 70 horse johnson

If you have a tachometer check to see what RPMs you’re running at WOT. If it's running more then 5500 get a bigger prop, if you’re not close to running 5500 then get a smaller prop. Figure approx 200 rpm change per inch of pitch. So if you’re running a 13 3/4 X 17 and your turning 5000 rpms, then get a 13 3/4 X 16 and it will turn approx 5200. Hope this helps.

 

[billfishfla]

Re: prop for 70 horse johnson

I have a 70 hp 2000<br /><br />Wish I didnt BUT it has Michigan wheel prop the serial number ends in - 02<br /><br />I have had nothing but problems with my engine and it is in the shop again <br /><br />2000.00 this time is what I am told <br /><br />I am praying he is wrong

 

[catfish1]

Re: prop for 70 horse johnson

diana25, seems i have seen this question asked on just about every area of this forum.<br />first we need to know the year of the motor, and the length of the boat. i am assuming you dropped the prop in the lake? in that case we can give you a starting point for a prop since you dont have any info on the prop you had. if i am wrong and you do have the prop! we need to know the pitch of the prop you have, and the wot rpm that you are presently running, along with the lenght of boat.