prop question

[wayne h]

i have a 9.5 evinrude that has trouble getting on plane i had a michigan 012008 prop on it i have 2 others that i have not tryed yet i dont know alot about props or the #s on them so i will tell you the other 2 i have and maybe some 1 can help me out the other prop is smaller <br />8x7 387334 <br />and this 1 is the biggest of them all but it had no #s just a messurement on the blade of <br />8 1/4 x 8 1/2 <br />any help will help like i said i have no idea what prop will do what thanks

 

[jdkzrt]

Re: prop question

Props are measured by diameter X pitch in inches. (your 8 X 7 would be 8 inches in diameter, and would theoretically push the boat foreword 7 inches in one revolution).<br />Your Michigan 012008 is 8 1/4 X 8.<br />This means your 8 X 7 would be the easiest for your engine to turn to get your boat up onto plane. You will loose a little top speed though.

 

[wayne h]

Re: prop question

my 8 1/4 x 8 1/2 has more blade surface area with flater more rounded blades<br />the Michigan 012008 is 8 1/4 X 8 was on the boat already and did not work well it more of a pointy blade <br />will the blade with more surface area help me more?

 

[jdkzrt]

Re: prop question

Pitch is the important measurement in this case, and you need less of it to help get the engine rpm's up. The 8 X 7 is what I would be trying first.

 

[wayne h]

Re: prop question

thats whats on there and it is not getting up thats why i am asking about the other props

 

[jdkzrt]

Re: prop question

I think you are getting your props and measurements mixed up. Your first post says you had the Michigan 012008 (81/2 X 8) on it and you had trouble. Then you say you had not tried the other two props. <br />You would be alot easier to undestand if you used your caps and . keys

 

[Spidybot]

Re: prop question

It really is not too complicated.<br /><br />As explained, the prop measures tells the dia and theoreticel distance per revolution.<br /><br />If the pitch is low, the motor will turn it easier as the distance covered will be shorter (like low gear bicycle). While covering less distance per rev. the low pitch prop also has a lower top speed at a given max. rpm<br /><br />If the pitch is too low it will allow the motor to run too high rpm (overrev), if too high it will not allow the motor to reach the rpm where it performs. It is IMPORTANT to reach the right rpm at WOT (WideOpenThrottle) - a figure that is always stated by the manufacturer as a range, ie. 5000-5500.<br /><br />If your boat setup & trim is right and your rpm is within the range at WOT and your boat still does not plane, your motor lacks power and you should look for a bigger.<br /><br />Much more (all you want to know) about this here

 

[wayne h]

Re: prop question

I have a 9.5 evinrude on a 12 foot aluminum v-hull that has trouble getting on plane.It has a michigan 012008 (dont know the messerments)prop on it.I have 2 other props that i have not tryed what 1 will be the best for me.<br />--8x7 387334-- very small with thin pointy like blades.<br />--8 1/4 x 8 1/2---this is the biggest and the blades are flatter more rounded.alot of surface area.<br />you guys are telling me that the prop i have on it is the best for that engine but its not getting me on plain.

 

[sharkcat]

Re: prop question

Hi wayne the answers to your post are telling you to try the 8 x 7. The smaller prop will give you better acceleration but less top speed.<br />Is your engine running well?<br />Are you with us or living in waynes world??LOL<br />Good luck

 

[wayne h]

Re: prop question

sharkcat if wayne was my name i might live in waynes world LOL remember just because the guy has a name on his shirt does not mean thats his name

 

[Boatman]

Re: prop question

Aw heck "wayne" take the boat out and do some trial and error. Try both props and see which one works best, if neither work, jump up to a 15 hp motor!<br />This is the fun of boat ownership, test and tune!!!! LOL<br /><br />Good Luck

 

[sharkcat]

Re: prop question

if a cat sleeps in a stable does that make it a horse??You dont have to be called wayne to live in waynes world.Its so nice to be insane no one asks you to explain...Hope you get your prop sorted