Prop starting point 40hp e-tec

[hazben]

I have a 1652AW Monark flatbottom boat, which I would guess weighs around 350lbs. I will be mounting a 2005 40hp e-tec tiller (240lbs) on this boat. The gas tank and battery are mounted in the front of the boat. I will be running mostly by myself (250lbs) and maybe up to 200lbs of gear. I am wanting to get a general idea of what size alum prop to start with. I realize I will have to run it and check wot rpms before choosing the final prop. My previous motor on this boat which was an 86 40hp Johnson had an 11 3/4x17 stainless prop on it and it performed well. Thanks for the help

 

[walleyehed]

Re: Prop starting point 40hp e-tec

Welcome aboard!!<br />Your E-Tec uses the same (basic) lower unit as the V-4's and uses the larger diameter props in 13 spline and I believe your gear ratio is 2.67:1, so in a 17 you'd be looking at a 13-1/4X17 to 14X17 depending on OEM or after-market.<br />I believe the 17 would be a good starting point, but I don't believe your old prop will work.

 

[hazben]

Re: Prop starting point 40hp e-tec

Walleyehed, thanks for the reply. I will let you know how it goes. Do you know if I would have to install a factory tach or would an after market work? <br />Thanks again

 

[walleyehed]

Re: Prop starting point 40hp e-tec

You can do as you wish on the tach, but I HIGHLY recommend OEM for accuracy.