Bent prop question

[singledoubt88]

Hello,

First off I am going to go ahead and apologize as i am a new boater with very little experience, so if i frustrate you guys with my inexperience im sorry. That being said I finally splashed my boat that i have been restoring for the past 6 months. I noticed a couple of problems.
The first problem I noticed is the boat was extremely hard to get on plane with two people on board. The boat is a 1977 16' starcraft super sport v hull with a 1978 85hp evinrude with pwr TNT. Second problem is the boat would porpoise badly even trimmed all the way down. I know that some of this is because my limited driving time, however after reloading i noticed the prop is bent on one of the blades. It is a 3 blade aluminum prop. I do not have the dimensions right now but will repost them in the morning, Here is my predicament. I do not currently have a tach, nor gps. I am wondering the best way to go about fixing my porpoising problem and the replacement of the prop. Should i buy a tach, and test the RPM's at WOT with a bent prop in order to determine the correct size? Will I damage the shaft? or should i replace the prop with the same size that is on it and then try to address my porpoising problems with perhaps smart tabs?

Thank you all,
MIKE

 

[Barnacle_Bill]

Re: Bent prop question

Get the prop fixed at a prop shop and go from there. That bent blade can affect performance and cause seals to go. So its not a good idea to run it until its fixed. Plus the prop shop can tell you what you have. Tach readings would really help a lot in determining the proper size prop.

 

[sublauxation]

Re: Bent prop question

You should be able to get an aluminum prop repaired for around $40. Fix it, get a tach (they're pretty cheap too), and go from there. Sounds like you'll need to make some changes in your set up maybe including a different prop, but at least you can use the fixed one as a spare. Even a small bend can drop RPM by 1-200. It took me a season to get used to how my boat handled in different situations, and proper tilt/trim, so don't be to quick in making expensive changes until you get the feel of it.

 

[singledoubt88]

Re: Bent prop question

great thank you. I was unsure of the integrity of the aluminum prop after it was reworked, also how can I tell if I have already damaged any seals? I ran it quite a bit before realizing that it was bent. i will definitely get a tach so i can see where i am at.

 

[sublauxation]

Re: Bent prop question

I'm no expert on determining bad seals, but did you notice any vibration while underway? Any grease/gear lube pools under it? You can watch the prop shaft spin to see if it looks straigth, but that isn't always a gaurantee, the back of one of my props isn't completely flat and looks like it's spinning crooked but the shaft is straight.