Prop Ventilating .

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Another update . I'm waiting on parts . The thrust washer from the old prop does not fit the new prop . I ordered new parts from iboats .
 
I received the correct thrust washer from iboat as well as a new castle nut that isn't very usable . The weather is improving so I'll get out on the water in the next few days .
 

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Went out for a test run this morning and the RPM seems to be a little better but the prop ventilating is pretty bad , So I'm in the middle of installing that jack plate .
It turns out the prop nuts I got from iboats were super glued together , I guess they have a prankster somewhere .
 
DarrellS said:
Went out for a test run this morning and the RPM seems to be a little better but the prop ventilating is pretty bad , So I'm in the middle of installing that jack plate .
It turns out the prop nuts I got from iboats were super glued together , I guess they have a prankster somewhere .
What rpms were you getting at wot?
 
About 4800 rpm when the prop would suck air and then rev to 5800 instantly . Right about 26 miles per hr on the GPS .
 
You have a prop issue. Someone since 1992 would have fixed that issue before you got the boat. Every prop has unique characteristics like cup, rake, diameter and pitch. Even if the paint comes off the prop can affect its performance so if your prop is old, it make be a bit worn out plus old technology. Plus if your blowing out it can be as simple as driver error. if you have a fishfinder with speed just watch that. keep bumping your trim up once on plane and you will see your speed rise. keep bumping the trim until your speed drops then bump the trim down once. your trimmed out perfectly.

On my big boat i have a 115 and i can blow the prop out everytime if i get to rammy, done proper prop hooks up bow lifts and she flys. Or switch to a 4 blade, better hole shot, will hook up alot better and better handling but you may loose 1-2 mph. And make sure your tach is pretty close. No way to know your proper rpms without an accurate tach.

Here is some good info on props.

https://bblades.com/props-101/
 
5-1/2 inch set back solved the problems I was having . I was even able to lift the engine another inch . 5500 rpm and 25 mph .
After seeing all the disconnected wires for the tilt trim and a nice trim gauge still on the dash I'm pretty sure this 30 hp evinrude was put on the boat to sell it .
When I went for the test ride the manual tilt was as low as it could go . When I started changing the tilt to help lift the bow instead of plowing the ventilation problems began .
I'm happy to finally have this issue done with .
Thank you for all the advice .
 

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