HELP: Why is my prop small?

[hckrphil]

Ok, I have a 1993 Mercury Force 40HP outboard. I've noticed that the prop on it looks small in comparison to alot of other outboard props. Is there a reason for this? Here is a picture of my prop (on the left) and the other props I have been seeing (on the right).<br /><br />

<br /><br />Thanks!<br /><br />~Phil

 

[TwoBallScrewBall]

Re: HELP: Why is my prop small?

More HP = bigger prop, for one. <br /><br />Also, if your prop has a lot of pitch, it will have a smaller diameter than another prom with less pitch.<br /><br />Don't worry, it's not the size of the prop it's how fast you can spin it that matters, right? lol.

 

[hckrphil]

Re: HELP: Why is my prop small?

The main question I had is...... why does my seem LESS DEEP than the other prop. I've seen 40HP engines with the deeper looking prop on there. Mine looks small and has that pointy nose cone looking thing on the end of it.<br /><br />Hmmmmm.<br /><br />~Phil

 

[wayne h]

Re: HELP: Why is my prop small?

looks like the prop is about the same size just that yours does not exhaust though the prop like the newer models do

 

[hckrphil]

Re: HELP: Why is my prop small?

Does that mean the bigger "looking" prop will not work on mine?<br /><br />~Phil

 

[LubeDude]

Re: HELP: Why is my prop small?

Im no expert on this engine, but I havnt seen a prop like yours for 20+ years. Me thinks you have the wrong prop. Did you buy it new like that? Or buy it used like that?

 

[JasonJ]

Re: HELP: Why is my prop small?

Your prop is not a thru-hub exhaust prop, nor is your motor. The pic of the other motor/prop you posted is a thru-hub exhaust, which is why it looks so much larger and meatier. On your engine, your exhaust is routed out from in front of the prop through that angled port that is under the cavitation plate and in front of the prop, whereas the more modern design has the exhaust actually running around the gearcase and out the prop itself. Two different systems, not interchangeable.

 

[Winger Ed.]

Re: HELP: Why is my prop small?

If you use the boat much, you'll more than likely be needing a spare prop some day.<br /><br />Most all of us had had rocks or stumps jump up and bite our props over the years. It's handy to just pull up on the beach, or hop out and change the damaged one rather than trying to get a tow.<br /><br />Go to a prop shop, a mail order catalog, or the mall here and get a basic Aluminum prop for your engine. You should see a few different pitches available for the engine--If you got a heavy boat for the engine, get a lower one, if your boat is real light for the engine, get one with a pitch on the upper/higher side of whats available.<br /><br />Run both, see which one does better and use it. Keep the other under the seat with a wrench to change it with if you need to sometime.

 

[roscoe]

Re: HELP: Why is my prop small?

You have the correct type of prop for your motor.<br />The lower unit is the old Chrysler design which was used on the 40 and 50 hp Force thru 1994. (?)<br /><br />A few guys have used a newer style thru hub exhaust prop on motors like yours. But they require a little special fitting and tinkering to get them to fit. Most shops won't take the time to do that, and no advantage to doing it, except perhaps a few $.

 

[LubeDude]

Re: HELP: Why is my prop small?

Looks like you have the right prop.