Props

[fragmag]

OK heres another newbie question. :grin: I was wondering if any of you guys keep an extra prop on board and if so, what is the best type to use? Also how do I find out what mine is? I know its a three blade aluminum prop for the 4.3l mercury mercruiser, but thats about it. Sorry if these are dumb questions, but I'm having so much fun with my new sea ray that I guess I want to know it all.

 

[STIHLBOLTS]

You can go to the sea ray web site and find the prop you have.
Go here.
http://www.searay.com/prop_charts.asp

You will need a couple of things besides just the prop.

A prop wrench, spare prop nut and kotter pin and block of wood.

 

[Dave M.]

I was wondering if any of you guys keep an extra prop on board and if so, what is the best type to use?

I suppose it depends on where you boat, but where I boat, I consider it a requirement to have a spare prop on board. It does not make too much difference about what it is, it is something that can get you home if your main prop gets mangled.

Also how do I find out what mine is? I know its a three blade aluminum prop for the 4.3l mercury mercruiser, but thats about it.

Looking it up on the internet will suggest what it should be. If you want to know what it is, go look at it. The numbers for the prop should be stamped into the prop hub between the blades. There should be two numbers, probably separated by an 'x'. They tell you the prop pitch and diameter.

You should also learn to take the prop off and put it back on. Do this on dry land. You might have to do it in less desirable circumstances someday, your safety could one day depend on your ability to change it.

You will find you need the prop wrench, which you should keep on board. You will obviously need a spare prop, if going this route. You need a wood block or other device to hold the prop from turning while you remove the prop nut. And you will need some tool to remove the locking device that holds the nut. I have never seen a Merc prop with a cotter key, but that may be what you need to remove. I have only seen the ones where the nut fits into a stamped plate where you bend a tab down to lock the nut. In any case, you need to have the proper tool to be able to unlock it to remove the prop.

Sorry if these are dumb questions, but I'm having so much fun with my new sea ray that I guess I want to know it all.

IMHO, its a very important question. Others may disagree, depends on where and how you boat.

If you are going to have a spare, you may want to consider one with a different pitch. For example, you might want one with less pitch for pulling multiple water skiiers, and one with higher pitch for all-out speed.

For my old 18ft Glaspar, I have a brass two blade and an aluminum three blade. For my 270 DA, I have two aluminum three blade standard props, one 21 inch pitch, the other 23 inch.

 

[fragmag]

Hey thanks for the answers. My prop is 14 x 23, so I'm guessing thats 14 inches diameter and a 23 degree pitch. I will look into getting those tools and a spare prop asap. Where I boat- Ft. Walton Beach/Destin area, the depth is anywhere from 20 feet to 2 feet especially around crab island. Once again thx for the info, but don't get too relaxed, I'm sure I will have a lot more questions for ya. :thumbsup:

 

[Dave M.]

The 23 number is pitch, but it is not degrees. It is the inches that the prop would travel forward through the water in one revolution if there were no prop slip, ie. the water did not move.

Another number you may want to find out is your drive ratio. It is the engine speed divided by prop speed, or how much slower your prop turns than your engine. For example, your drive ratio might be 2, so when your engine is turning 4000, your prop is turning 2000 RPM. So a 23 inch pitch prop would be advancing 23 inches/rotation x 2000rotations/min = 46,000 inches per minute. That would be your boat speed, except the prop slips some in the water. Maybe 10 or 15 percent, maybe more.

There are prop calculators on the net that you can use to calculate these things. Here is one.

If you look around in the boating shops you may find a nice plastic prop wrench that fits your prop nut, is light in weight, and maybe even floats if you accidentally drop it in the water while changing a prop.

 

[Larry&Leisa]

Not a dumb question at all.. I just learned a whole lot that I had been wondering about! :thumbsup:

 

[First Born]

Here is what I did when I was going through the same question that you have. I went to the local dealer and told them that I wanted to get a spare prop. He suggested going with a different prop and using the stock prop as my spare.

Some people will go different ways on this, some will suggest stainless or alluminum. Personally I wanted alluminum because I have read that it will give more than stainless although you probably get more out of a stainless prop.

The service manager at the time told me that he had a lot of people with the 185 going with a 4 blade alluminum (quicksilver) 14x20P prop. So I bought that one and now use the 14x23p 3 blade as my spare.

To be honest I do not see alot of difference but that is what I did.

Just something to think about.

Wesley

 

[Dave M.]

The service manager at the time told me that he had a lot of people with the 185 going with a 4 blade aluminum (quicksilver) 14x20P prop. So I bought that one and now use the 14x23p 3 blade as my spare.

Wesley

I will make some guesses about Wesley's props.

The four blade prop will have more drag at high RPM in the water than the three blade, so other things being equal, would tend to reduce the wide open throttle RPM.

The four blade prop has less pitch, so will be easier to turn in the water, as it will try and move less distance. A prop with less pitch, other things being equal, will increase your WOT RPM. This is opposite the above at planing speeds or WOT.

The four blade prop with less pitch will probably slip a bit less at speed, so this will partly offset the lower speed from the lower pitch.

So it may all be about equal on plane and at WOT.

I would expect a difference in 'hole shot', or getting on plane, especially if pulling skiers or tubes. The four blade prop has more blade area in the water to move water, and it has less pitch so it is geared lower. This should give more low end hp to the prop, as the engine can spin faster for the same prop movement distance through the water.

These are my guesses. Don't believe anything you read and only half of what you see.

 

[wish2fish]

while I guess it might be appropriate for some people to have a spare prop I really wonder if it is worth carry onboard. I can see bringing it with you on a trip so as not to ruin a weekend or week. I can't imagine on a smaller boat it is worth giving up the space or carrying the weight all the time.

 

[First Born]

wish2fist is correct at least for us. I carry it with us when we go to the lake for a weekend. I do not carry it with us on the boat. The lake that we go to for the weekend is known for tearing up a prop and that is the main reason that I wanted a spare. If we had a problem I would get a tow back to the house and then take it out of the water to change so that we could be back in the water in about 15 minutes as opposed to ruining a weekend. :thumbsup:

Wesley

 

[searay sport]

Hey thanks for the answers. My prop is 14 x 23, so I'm guessing thats 14 inches diameter and a 23 degree pitch. I will look into getting those tools and a spare prop asap. Where I boat- Ft. Walton Beach/Destin area, the depth is anywhere from 20 feet to 2 feet especially around crab island. Once again thx for the info, but don't get too relaxed, I'm sure I will have a lot more questions for ya. :thumbsup:

Wow, that is shallow, I am new to boating, so I am taking it careful. I slow down when I get under 20 ft. Our lake is very deep 300 ft is about the most I have been in, but have only been out 5 times so far. I am glad you asked about the prop. I asked when we bought the boat, and was told the propr on the boat was about the best for hole shot, and max speed, so I will save my 500.00 for gas money.

 

[fragmag]

Yeah we took the boat out yesterday for its maiden voyage. It was fantastic, but a few times we got into water the was a little over 2 feet deep. Scary stuff for a new boater like me. :smt101

 

[280 SeaRay]

This is a great question. You took the maiden voyage on friday the 13th .... very cool!!

You have the alpha drive.... so if you plan to carry a spare prop you should really consider carrying the spare flo-torq hub kit as well. If you hit something hard enough to damage the prop the flo-torq sleeve has likely broken free or spun. And putting a new prop on a spun flo-torq is still not going to get you anywhere :smt001

Among a good deal of unrelated spares, I carry 2 spare props, 2 flo-torq kits, a floating prop wrench and a mesh bag that I tie to my arm to place parts in as I remove them in the water. This allows me to easily change the prop and hub assemblies in the water if required.

The beauty of the alpha drive and various props is that finding a demo prop dealer is usually very easy. Here you can try before you buy.... so if you wanted a watersports prop like Dave mentioned which could also be used as a spare you could try several and see which one you like.

I practiced removing the prop on the trailer a few times... to become familiar with the process..... then when backed into a beach in nice shallow water I also practiced the removal and replacement process. Not hard at all. I will be adding a simple snorkel kit so I can keep my eyes in the water while performing the process.

wish2fish... alpha props (especially aluminum) are much much easier to store than the fun (and bulky) BIII props.... having gone from a BIII in the last boat to twin alpha in the current boat.... storing alpha props is a dream :wink:

 

[wish2fish]

Jeremy,
Previous boat was 1989 160. Had decent storage for the size of boat but I couldn't imagine giving up the space for something you might never use. First day out on the 160 I damaged my prop where about 1/2 the blades were left. I limped back about 10 miles at idle speed. Bad luck first day out but nothing like that ever happend again in next 18 years.

FYI, 1988 was a drought year here. Friend told me he had hit something in the water in that area. I thought he said it was on the other side of the river so I intentionally was avoiding the area I thought the object was. We were riding along at 25mph about 50 yds off shore and wham. Turns out it was part of an old temporary concrete wall that was left behind when they built the current dams on the Ohio River. Water was way below normal and made the object shallower. I never understood why the object doesn't have a bouy to mark it!