Prop slowing me down?

ekinnee

Seaman
Joined
Jul 24, 2008
Messages
62
Re: Prop slowing me down?

it may be on the side or on the inside on the center of the hub ring. If it is inside you will most likely have to remove the nut and collar to read it.
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: Prop slowing me down?

Are you capable of determining if the engine is actually running correctly? When was a tune-up done last? It is amazing the number of people that can't tell if an engine is down a cylinder or two. The boat may also be full of water soaked foam. Check the prop for diameter and pitch or a manufacturers part number. Was the outdrive ever replaced? If so it is entirely possible an outdrive with the wrong gear ratio was installed.
 

hardwire

Cadet
Joined
Aug 16, 2008
Messages
9
Re: Prop slowing me down?

The engine has less than 30 hours on a new rebuild so I can hopefully assume compression isn't a problem. I will have to put a compresion gauge on it later today once it stops raining. The outdrive is original as far as I can tell. The serial number matches what is scribbled down in the boat's owners manual. I have heard of boats with water soaked foam, and that seems like it may be a good possibility since it does take on quite a bit of water (still working on that one :))

How do I check the foam? Do I need to pull up some floor panels?

Can a mismatched prop cause this low of a WOT RPM by itself, or does it sound like a combination of multiple problems?
 

Firestar

Chief Petty Officer
Joined
Aug 20, 2006
Messages
530
Re: Prop slowing me down?

You need to find the pitch of your prop. It should be stamped on the hub. I would guess a 19P or 17P would be stock size. If you have higher and it being chewed up,
that may have something to do with your problem too.
 

hardwire

Cadet
Joined
Aug 16, 2008
Messages
9
Re: Prop slowing me down?

Well I got the prop off, and the numbers stamped on the hub read 48-38440-19. Does that mean it is a 19P? This thing looks awfully chewed up inside. The splines seem alright, but on the inside of the hub where the shaft goes on the back of the prop (towards the front of the boat) it looks pretty hammered.
 

Firestar

Chief Petty Officer
Joined
Aug 20, 2006
Messages
530
Re: Prop slowing me down?

It's a 19p. Get a new one and you'll be good to go.
 

hardwire

Cadet
Joined
Aug 16, 2008
Messages
9
Re: Prop slowing me down?

So assuming that's the correct size, I guess my problems lie elsewhere. I am thinking that I have a bunch of soaked foam underneath the floor. The decking is in good shape and I hate to pull it up, but what's the best way to start yanking the deck up so I can check underneath it? Saw it out, or can I pull it from one side with a crowbar or something?
 

hardwire

Cadet
Joined
Aug 16, 2008
Messages
9
Re: Prop slowing me down?

Well I think I may have found my culprit. I put the compression gauge on her today and got 125, 120, 120, 90. Looks like the number four is dead.
 

Robj

Lieutenant
Joined
Mar 22, 2007
Messages
1,441
Re: Prop slowing me down?

Those do not look like rebuild engine nos to me. Maybe post in the engine section for suggestions.

Have a great day,

Rob.
 
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