Prop question 82 Evinrudem 90HP

B

bo32792

Cadet
Joined
Mar 13, 2005
Messages
8
I have a stainless steel prop on now that looks to have been ground down a few times, plus it is nicked up pretty bad. At close to WOT the boat went around 20MPH. I have been looking at other posts, but I am still confused on what type of prop to get. The boat is a 16' fiberglass trihull runabout. Thanks for any info you can provide.<br /><br />Bo
 
LubeDude

LubeDude

Admiral
Joined
Oct 8, 2003
Messages
6,945
Re: Prop question 82 Evinrudem 90HP

Wow, ya know, you have come real close to saying,<br /><br /> "I have a boat and I need a prop"<br /><br />We need LOTS more information:<br /><br />What type boat<br /><br />What engine<br /><br />What RPM at WOT <br /><br />How do you use your boat<br /><br />Where do you use your boat
 
B

bo32792

Cadet
Joined
Mar 13, 2005
Messages
8
Re: Prop question 82 Evinrudem 90HP

The boat is a 16' fiberglass trihull that sits very low in the water. The motor is an 82 Evinrude 90HP v4. The RPM was around 5000 when tested with the old prop. The boat is going to be used mainly for fishing. The problem is it's only been in the water once since I bought it, and that was for testing purposes. Some engine work and lower unit was done before this and I knew the prop was in bad shape. <br />I hope this is enough info<br />thanks
 
M

Muddy Paws

Seaman Apprentice
Joined
Mar 20, 2005
Messages
31
Re: Prop question 82 Evinrudem 90HP

What is the diameter and pitch of the current prop?<br /><br />These numbers should be on the hub next to the prop nut.
 
Silvertip

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,762
Re: Prop question 82 Evinrudem 90HP

Something is amiss with the numbers so I'd be looking at other things before swapping propellers. 90 HP, 20 mph, and 16 ft simply doesn't make sense (at least to me). 5000 rpm would indicate the prop is close to being correct as that's about the rpm range the engine should run at. However you said "about 5000". If you mean 4500 then the engine is lugging. If you mean 5500 you are at the top of the range. An incorrect tach reading may play into this as well. Trim setting, hull condition (bottom condition/trapped water below deck), engine tune, all are factors in boat performance.
 
You must log in or register to reply here.
Top