Prop type and size for Yamaha 300

Vikingstaff

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Thks so much for info yes the boat is very heavy I run with full tank of gas (53) gallons & I have F200 should have went with Vmax 200 the dealer said he raise the engine & change to ss prop if they can get one Thks again
Both of those moves will help…particularly switching to a SS prop. Any pontoon motor above 115HP should have a SS prop as the aluminum otherwise flex and lose thrust.
 

Skipping Scallop

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All great points... I will keep you posted as to what happens. I did just order my Edson Power Knob for the stainless steel corvina wheel ( Brown ). I called them directly and gave them the size of the diameter of my wheel. 1.5 inches. That requires a special length band. They said they had one that will fit it. All other ones are to small to fit just as an FYI.
 

Turbojack

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Getting a boat dialed in can be a big project between raising the motor up a notch or two and finding the right prop. Finding a place that will let you try different props is a challenge. Two different props can have the same specs but more cup on one can make a big difference. Also being set up for the time of year can make a big difference since you will not have the same amount of HP when temps are in the high 90's vs 70's
 

Vikingstaff

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Turbojack is right, particularly if you are going to try to dial it in 100%. Some bother. Some do not.

My advice (which is literally only worth 2 cents…) is don’t rush it. Just treat it as the slow break-in to getting to know your boat.

Request the best informed “guess” prop you can plan for initially, track numbers in early outings. If its not giving you the performance your boat+motor combo is capable of, slowly dial it in through a little trial and error.

By mid or late summer (depending on boat time and prop availability), you’ll be there. And you be on the water while doing it.
 

Skipping Scallop

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Getting a boat dialed in can be a big project between raising the motor up a notch or two and finding the right prop. Finding a place that will let you try different props is a challenge. Two different props can have the same specs but more cup on one can make a big difference. Also being set up for the time of year can make a big difference since you will not have the same amount of HP when temps are in the high 90's vs 70's
14.25 diameter 17 pitch is what is on there. I was hoping for 15.25 diameter. Yes your right. The way things are now with products/props I will try it and ask if they have the larger one they can bring if possible to switch out. 300 hp will have the torque. I will post my findings when we go for the first trial of the boat and make sure everything is good. I'm very excited..... Thank you.
 

Potomacbassin’

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14.25 diameter 17 pitch is what is on there. I was hoping for 15.25 diameter. Yes your right. The way things are now with products/props I will try it and ask if they have the larger one they can bring if possible to switch out. 300 hp will have the torque. I will post my findings when we go for the first trial of the boat and make sure everything is good. I'm very excited..... Thank you.

Sounds like you have a Yamaha Reliance.

COMPLETELY WRONG PROP for your boat!

We have seen this multiple times on this forum, myself included. Dealer sticks what they have available that is a moderately sufficient and claims performance numbers that are in the general ballpark of what you would expect. It's not a crappy prop, quite good in fact. But for a lighter model I4 engine. You are losing a ton of hole shot and efficiency at cruise, while top speed you're giving up 3-4mph if not more.

Because it's a smaller prop you're just wasting that HP - like putting skinny tires on a Corvette, it'll eventually get up to speed but spinning out the whole way. I would demand a prop that is designed for your 300hp V6 - SWS or Enertia will have the blade area to take advantage our your motor. Availability will be tough, but get your dealer to commit to the correct prop.

You can also ask the dealer to reimburse you if you can source it yourself. Can't really trust anyone but yourself to make this a priority.
 

Skipping Scallop

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Thank you for the information! I am completely in the dark in this area and agree with you. They keep telling me engine all the way down so no cavitation and with this prop only loosing 1 mph. The props your looking at seem to be going for around $650. What Prop size and pitch would you recommend? I was thinking 15.25 x 17 pitch. It's a larger prop that I think would do what your stating. I agree I want the 300 performance not the 200 performance.
 

Potomacbassin’

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My recommendation would be to start with the 17p on either the SWS2 or Enertia props. You'll have more than enough HP to hit the rev limiter lightly loaded, but you'll want to see how she performs with your max load. If you still hit the rev limit then you can increase your pitch. Your cost estimate is correct, although given inflation and back orders it wouldn't surprise me to see it get into the $700 range.

I tested a 16p and 19p SWS on my F250 and achieved 6000 and 5300 rpm, respectively. My current 17p Enertia hits 5700-5800 which is almost perfect. With your extra 50-ish HP you'll likely get another 300-400 rpm so I think you may be able to turn an 18p.

Consider raising your engine 1 hole as well to wring out that last bit of fuel efficiency and speed. The props sit so low on our boats that a 3/4 inch change in mounting height should not ventilate.
 

Skipping Scallop

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My recommendation would be to start with the 17p on either the SWS2 or Enertia props. You'll have more than enough HP to hit the rev limiter lightly loaded, but you'll want to see how she performs with your max load. If you still hit the rev limit then you can increase your pitch. Your cost estimate is correct, although given inflation and back orders it wouldn't surprise me to see it get into the $700 range.

I tested a 16p and 19p SWS on my F250 and achieved 6000 and 5300 rpm, respectively. My current 17p Enertia hits 5700-5800 which is almost perfect. With your extra 50-ish HP you'll likely get another 300-400 rpm so I think you may be able to turn an 18p.

Consider raising your engine 1 hole as well to wring out that last bit of fuel efficiency and speed. The props sit so low on our boats that a 3/4 inch change in mounting height should not ventilate.
Great Information! Thank you for the straight scoop. When we do the first trial with the boat before I take it home I am bringing two other guys, the rep and myself so that should give me an idea with some load.
 

David G

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I have researched best prop for a 25' tri-toon w/ 300 yamaha
Here is what I found for best overall performance
15 pitch 4 blade
or 15.5 by 16
or 15.75 by 15
 

Skipping Scallop

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Wow who would think so many variables. It would be great to test them but like mentioned. I'm sure they will shrug it off and say that size that's on it is the correct one.... I have kept all of the post info, I will dial it in some how. I just don't want to spending $700 per prop just to test.
 

Potomacbassin’

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Wow who would think so many variables. It would be great to test them but like mentioned. I'm sure they will shrug it off and say that size that's on it is the correct one.... I have kept all of the post info, I will dial it in some how. I just don't want to spending $700 per prop just to test.
Yeah that's rub. Fortunately for me the dealer took back the Reliance and sourced me the SWS 19p. I wanted to test a 17 but he said it was all he had laying around and was happy to order another if it didn't work.

Too much pitch so the search continued. I purchased a Quicksilver Q3 (exact same as a Mercury Enertia, just different name) from Ken at Propgods, and asked the dealer to take the 19p back and order me a 16p for my spare. So my only out of pocket was essentially a spare.

I get it, I was lucky to travel that circuitous route and be able to test a bunch of props, but the benefit to the community is test data on the forum. Many others have also contributed their test data and posted it here so there's at least a good head start for newer owners.

Lastly Propgods runs a prop test program where you only get charged $40 to swap into another one. Added benefit is Ken is super knowledgable and will help you get your prop dialed in without a lot of trial and error.

Good luck and let us know what your numbers are when you get some!
 

David G

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I got this info from prop gods and watching you tube videos, All these I list have very close to the same result.
 

Sheepdog

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If your boat is like mine that larger / heavier engine will squat the stern quite a bit, so there will be a bit more drag than a lighter I4 engine (200 HP and below). Therefore raising the engine at least one position is worth trying. I raised mine to 2nd highest and still don't ventilate the prop even in turns. Note - my 17p Mercury prop is 14.5" in diameter, while a Yamaha SWS 17p prop is 15.5". If you do end up getting a SWS then raising the motor to the higher positions could cause ventilation due to that extra half inch radius.

Also props have different design characteristics besides pitch and diameter so be aware of that as well. I tested two SWS props (19p was too much, have a 16p as my spare) and while they have more "bite" and better hole shot than the Mercury prop due to the larger diameter, they have much lower top speed and less fuel efficient at higher speeds. Consider trying an Enertia prop if top speed and fuel efficiency are priorities for you.
I have a 25R w/ 250 v8 Mercury. Using 14.5 x 17”enertia. Max speed 43.5@5700 rpm. ( dual bikini’s, power pole, trolling mtr and 4 batteries)
 

Turbojack

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I just changed to a saltwater series 15.5 x17P prop. The one that was on the boat was a 14.25x17P Difference is night and day. Since putting new prop on the miles per gallon does not go below 2.4 Before I say 1.4-1.7 a lot. The top RPM on 100 degree day outside Houston was 5500, where before the RPM was 5900 at 3/4 throttle. Before was lucky to see 40, now runs 45+ and had 2 more people in the boat. Cruise RPM came way down. Later this year I will raise the motor up 1 notch and see what happens.
 

Potomacbassin’

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I just changed to a saltwater series 15.5 x17P prop. The one that was on the boat was a 14.25x17P Difference is night and day. Since putting new prop on the miles per gallon does not go below 2.4 Before I say 1.4-1.7 a lot. The top RPM on 100 degree day outside Houston was 5500, where before the RPM was 5900 at 3/4 throttle. Before was lucky to see 40, now runs 45+ and had 2 more people in the boat. Cruise RPM came way down. Later this year I will raise the motor up 1 notch and see what happens.

Sounds like you had a Reliance prop. Dealers need to stop putting these on the higher HP outboards, they're going to give these boats underwhelming performance.
 

LaurencetheAdventurer

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I just changed to a saltwater series 15.5 x17P prop. The one that was on the boat was a 14.25x17P Difference is night and day. Since putting new prop on the miles per gallon does not go below 2.4 Before I say 1.4-1.7 a lot. The top RPM on 100 degree day outside Houston was 5500, where before the RPM was 5900 at 3/4 throttle. Before was lucky to see 40, now runs 45+ and had 2 more people in the boat. Cruise RPM came way down. Later this year I will raise the motor up 1 notch and see what happens.
Maybe put your data in List Your Specs Here thread - could be very useful for Members!
 
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