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My ongoing prop ordeal

E

ejbtech1

Regular Contributor
"ok....I talked to the local V

"ok....I talked to the local Vovo dealer/repair shop.
They are telling me to go with a 16x15 LH prop as opposed to the 14x19 that I have. They say that will bring me up out of the water and to the speed I want to go.
BUT........They say they really want to see the boat.
Can a 16x 15 work on a 270? Is there enough clearance? They also told me they can't figure out why my long hub only has a thin plastic washer and no line cutter or spacer.
I kind of thought the 16 would "smack " the outdrive on rotation.
Anyway, they are saying it will work, and the new prop will cost me 189.00. They say that is my no power problem. And that this prop will make the boat "come alive". Anyone?"
 
"Eric,

A 270 outdrive &#40

"Eric,

A 270 outdrive (and a 280 and a 290 as well) can accommodate a 16" diameter prop, but I would be very surprised if the prop they recommend would work in your boat. In my view, your engine (110 HP) will not have enough power to push it with a prop of that size when it could not take off with a 14 x 19.

I used to have an AQ140A (125 HP) on a 17.5 fiberglass hardtop boat and I ran it with 14 x 16 or 15 x 15 props up to 25 knots. Also, if your boat is the one you have in your profile ( 21' )then by all standards you are really underpowered with 110 HP. Most boats of that size do have a minimum of 200 HP engines. Is that really your size of boat (21'?)


Please go to this link

http://www.miwheel.com/MIWheel/pdf/obsd_03.pdf

and see that for 110 HP - 140 HP engines running on 18'-21' boats the recommended props are 14 x 15 and 14 x 17. Yours, being 110 HP, I suspect will have to go with 14 x 15, and that may be even too heavy.

In any case, if you really want to give it a try to that prop, I suggest you tell the VP guys that you will only buy it if it works after testing it. Then you won't be stuck with something you cannot use if (when) you find it doesn't work."
 
So I should probably stick to

So I should probably stick to switching over to a 14 x 15 prop. And ignore the other suggestions. Right?
 
"Eric,

Getting the right pr

"Eric,

Getting the right propeller for a said application is a combination of science and art, and it takes quite a bit of testing. In my last two boats I have tried a number of different propellers (I don't recall how many, but probably no less than 6 on each) until I found the one that performed best for my intended application. When I test propellers on a said boat, I analyze factors like holeshot and top end speed, but also thrust at lower RPM and (most important) fuel consumption. I collect data at different RPM, analyze boat and engine performance, and then I make a decision. More often than not, the prop I end choosing for the application still needs to be modified: sometimes adding/removing pitch, and sometimes adding a cup. I am lucky enough to know one guy who owns a propeller shop and has different sizes and types of used propellers, so getting two or three props to test them (free of charge) is usually not a problem for me, because at the end he knows that when I make the final selection I will usually ask him to make for me two identical props.

Back to your case, it seems to me that you have a very underpowered boat. If you ever make it plane with 110 HP, it is going to be with a very low pitch propeller, and that is why I suggested the 14 x 15 as a starting point. This does not mean you should not try larger diameter props (say 15 x 13") so that there is more thrust when attempting to plane. But honestly, I feel that 16 x 15 is too large. Again, if you can try it for free, it makes sense to see the results by yourself. I also hope that your boat has trim tabs, because you are very likely going to need them. Another thing that yo have to keep in mind is that, in addition to pitch and diameter, there are more things to a propeller: rake, blade width, skew, etc. In your particular case I would definitely select a prop with a wide blade and stay away from what Volvo calls the "speed propellers", which are props with narrow blades. See this thread for more information:

http://www.marineengine.com/discus/messages/12487/70730.shtml

Lastly, keep in mind that neither I nor anyone knows it all; so when it comes to suggestions, it is up to you to analyze their merits and to follow (or not to follow) them accordingly."
 
"jumping in here el I recieved

"jumping in here el I recieved a post from you recomending a few things on my prop.I thought i saved it but cannot find the reply from you,it was in regards to my prop size and you recommended a 15x19 I thought i could access this info.i have done a search and am not able to find the response.do you have it still on file.just wanted to know in your experience what my boat would do with a 15 x 19.thanks"
 
"Ok I made a trip to a well kn

"Ok I made a trip to a well known prop Shop here, and they had a 14 x 15 prop in stock and a spacer
so I bought it. going to put it on tonight and try it on saturday. the owner told me if it doesnt work he would refund my money. He says that is the one i need. He also told me that I might even gain 1200 rpm. But should at least get 1000 rpm out of it. He seems to think that I should be able to get on plane fairly fast. Oh and, yes my boat is a 21 footer. meant to say that in my last post. I guess I will find out what the Prop change does and post again soon. Thanks for the help I know I will need more soon."
 
"Have you tried to trade-in yo

"Have you tried to trade-in your current prop during the transaction? It is usually a neat way to get a few $$$$ back, which no doubt you will need as long as you own a boat (especially if it has a Volvo Penta engine and drive installed
biggrin.gif
).

Looking forward to see the test results, and to the fine-tuning that no doubt will come afterwards."
 
I AM GOING TO HANG ON TO THE P

I AM GOING TO HANG ON TO THE PROP FOR A BIT. I WILL PROBABLY END UP SELLING IT ON E BAY. or on here if anyone reading this post needs a good used prop of this size. thanks for the help. I WILL let you know what happens after the test run.
 
"Eric, if you end up selling y

"Eric, if you end up selling your 14 x 19 prop and it is a short hub, let me know...I'm interested. Thanks."
 
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