Re: Porpoising 16' semi-v w/ 40-HP Mercury need help have pictures
Whoops sorry about that!!! Thanks again for all the help. If I'm understanding everything correct you guys are saying a 10" dia 15" cupped prop should do the trick?
Like I told you or someone else on here in the last day or two, cupping usually amounts to an additional inch of pitch at WOT. So 15+1 = 16 which was my best guesstimate! And I also said that you probably will need the cupping but didn't push it as I didn't expect you to have much luck finding a cheap, cupped, alum. prop for a 40 hp engine. So go and get your 10x15 cupped prop and have fun!
Go back to the iboats propeller selector and this time punch in 15 for pitch.
Go down to Hustler. Prop #2130 1510 plus Hub #11. Geez better price yet $98.24 It doesn't list the hub separately so possibly that's the price for both....I mean yo can't run the prop without the hub.
Now double click on the word Hustler in left column. Then on that page, down below the pic of a prop, look for the tab marked "Product Info". Carefully read through this and you will see what this prop can do for you. It IS cupped like they do on the bigger props for bigger engines.
In that info guide, they also indicate that the 1510 is ported. Ported means small holes are drilled in the barrel below the leading edge of each blade. Porting is usually a good idea on heavy boats that are hard to plane but use a lot of pitch at high speed as they have little drag....aka padded bass boats. You have a lot of weight and a pad bottom which doesn't come out of the hole very well so you don't want much pitch. Once up and running you have very little drag on the pad and you want lots of pitch. You can have both by porting a high pitched prop and that is why they get (some mfgrs do) ported.
On your boat, with all your weight in the stern it might help you even though you have a nice flat hull at the transom that planes out easily. Actually it could allow you to increase your pitch an inch or two. But for now stick with the Hustler 15p cupped. The ports allow the engine to rev up slightly over normal in the hole shot which allows you to develop your HP faster which turns your prop harder and pushes you out of the hole better. Once up and running the holes seal off and you don't know they are there.
However, if you do buy the Hustler and do find yourself overreving in the hole shot, and it not caused by ventilating (sucking air in from the surface) with the engine height you have, then you may choose to just seal the holes. JB weld will seal them right up for you and solve that problem.
Edit:
I checked the shipping onfo again and it looks like you will get all that you need to install and run the prop. One additional thing in your carton will be a spacer. This spacer is to ensure that the removable hub type propellers fit prop shafts (length) designed for rubber type pressed in hubs, like were used years ago. The important thing is to ensure that the prop spins freely when installed and is tight on the prop shaft. On that sized engine probably 40 ft-lbs of torque would work. My 90 is spec'd at 55.
If they don't indicate otherwise, the spacer will go on before the nut and lock washer and may replace the existing tab lock washer on your engine currently. The way you will know is just see how the spacer and nut fit the splined shaft. You want the tab washer on the spline, as it is splined, and you need threads for the nut since it is threaded. Use your best judgement. Just wind up with a tight fitting prop on the shaft.
Mark
