Trippernsc
Well-Known Member
I need to take a look at that. Highest RPM I hit at WOT was 5,500 which sounds like I many not have the correct prop (but i'm no expert so correct me if I'm wrong).
How fast should my pontoon go?
- Thread starter Matthewstm
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Vikingstaff
Moderator
Curious to hear what prop and prop pitch size you have once you share it with us.
Once broken in completely, track it at WOT again a few times. Does it stay around 5500 RPM’s on a lower lighter load in smooth water at that time? Not to mention, if you will often run with a little heavier load, then RPM’s will come down further anyways. Hence, I always think its nice to get right near the top of RPM range at WOT on the lighter load. Gives you flexibility for however you’ll use the boat, while getting the performance you paid for.
Your motor can go up to 6000 RPM’s at WOT. So generically you can go down 2 in pitch, and RPM’s should come up about 400…maybe 500 RPM’s and put you where you want to be. That should translate to even better performance manners.
Typically your RPM’s go up about 200 to 250 for each -1 in pitch, or coorspondingly your RPM’s will go down 200-250 RPM’s for each +1 in pitch that you switch to. Numbers vary somewhat based on type of prop and other factors.
I believe these are your specs from Yamaha:
Trippernsc
Well-Known Member
If I drop a couple in pitch, what will that do to my top end speed?
Vikingstaff
Moderator
Wont really know precisely until you do it. Speed is not as specifically predictable as the RPM part of that equation.
Also, type of prop makes a big deal in that regard: some are designed and cupped for hole shot, or mid-range performance and efficiency, or balanced performance, or top end speed at WOT etc… And 3 or 4 blade makes differences in these regards as well. I am assuming traditional 3 blade props in this discussion.
My armchair guess would be anywhere from 3-6 mph dropping 2 in pitch. It can vary somewhat wildly. Chance it could be more, but those MPH gains are usually small and incremental.
You should gain something in speed, but probalby the biggest reason to dial it in is to run the motor optimally, AND have the most RPM range flexibility when loaded up with people and gear. Plus, for me , I just think if someone is going to pay for a 150HP or MORE HP motor, they might as well dial it in to get what they paid for out of it.
That said, I personally like the speed increases, so that always motivates me.
Trippernsc
Well-Known Member
Wont really know precisely until you do it. Speed is not as specifically predictable as the RPM part of that equation.
Also, type of prop makes a big deal in that regard: some are designed and cupped for hole shot, or mid-range performance and efficiency, or balanced performance, or top end speed at WOT etc… And 3 or 4 blade makes differences in these regards as well. I am assuming traditional 3 blade props in this discussion.
My armchair guess would be anywhere from 3-6 mph dropping 2 in pitch. It can vary somewhat wildly. Chance it could be more, but those MPH gains are usually small and incremental.
You should gain something in speed, but probalby the biggest reason to dial it in is to run the motor optimally, AND have the most RPM range flexibility when loaded up with people and gear. Plus, for me , I just think if someone is going to pay for a 150HP or MORE HP motor, they might as well dial it in to get what they paid for out of it.
That said, I personally like the speed increases, so that always motivates me.
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Timdelta
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This Q25 goes so fast it scares me. I’ve hit 41 in choppy water and double Bimini with a headwind. I’m at 8.1 hours now.
Potomacbassin’
Well-Known Member
Looks like you have a Yamaha SWS prop?
You're right in the middle of where Yamaha wants you, so no need to change unless you're unhappy with performance. And dropping pitch with another SWS prop will likely not lose much speed as you'll gain RPM up to your rev limiter. Kind of like dropping a gear in your car, at that moment you'll travel as fast as before but just with higher engine RPM. Now if you were well under 5000 RPM and outside peak torque then dropping pitch could pick up speed (partly due to less drag from the larger diameter prop) not to mention make your engine happier.
As you've probably read here a few times switching to an Enertia prop in the same pitch will pick up a few MPH but tradeoff a little holeshot and a little fuel efficiency in your cruising range. Raising the engine will also give you straight-line benefits (speed, fuel efficiency) but potentially cause ventilation in turns or turbulent water.
ABOUT 75 ON THE HIGHWAY
Trippernsc
Well-Known Member
I feel like I'm good where I'm at. Hole shot is good, top speed is plenty (let's be honest, I won't be hitting WOT with the Mrs in the boat). I'm going to leave it alone.
BigKahuna
Well-Known Member
We don't like going upper 30's/40 with the double bimini open. It handles it but we don't want to push it!
Hi Mathewstm … I have a similar setup to yours. I have a 2020 23Q ESP Pkg w/ Yamaha 250 SHO. At WOT I hit 48mph @5800rpm on smooth lake, no wind, 3 adults, 50+ gallons of fuel & Bimini top up. SS Saltwater Series prop but I don’t recall the pitch.
I believe you should be seeing similar performance results.
I believe you should be seeing similar performance results.
Timdelta
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How much do you think double Bimini hurts top speed? Has anybody figured that out?
Jack M
Moderator
It has to hurt some . Only one way to find out.
CLDave
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Standard PSA to not run top-speed with your bimini up (extended) - especially with the electric units. They're only rated to go 30mph.
Potomacbassin’
Well-Known Member
I'm sure someone here can give an exact number, but I'll add an unexpected (at least to me) result on my boat - single bimini. Normally to get max top speed you're trimmed fairly high and reducing the amount of running surface on those toons. For me it's around 50-60%.
But with the bimini up, this high-trim position angles the canvas into a sail creating an enormous amount of drag. So I actually GAIN speed when I trim down and allow the bimini to be as horizontal as possible and not catch wind. IIRC probably around 3-4mph difference.
LaurencetheAdventurer
Well-Known Member
CL Dave and I have the same engine and Benny Length: I am 10mph slower with Bimini up, 4 extra people, and probably a few hundred pounds of extra stuff.
BigKahuna
Well-Known Member
With just my wife and I we have had our boat hit 42 (GPS) with both Bimini's in their boots and in the trailer position. We regularly go mid 30's with both Bimini's deployed. We don't like to push it.....
Timdelta
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I hit 42 yesterday with 32 gal of fuel and 8 gal water tank, a potty full of pee and two people who had way too much coffee. Both biminis out and calm wind and water. I will do some real testing once break-in is done. I didn’t mess with trim, it will be interesting to get some real data.
I’m thinking calm day, water and slack tide. Run 1/2 mile in each direction to get baseline and then again with one up, one down and then with both down. May have to be with a another guy, cause wife won’t go for this sort of science fun.
I’m thinking calm day, water and slack tide. Run 1/2 mile in each direction to get baseline and then again with one up, one down and then with both down. May have to be with a another guy, cause wife won’t go for this sort of science fun.
Matthewstm
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Everything is clean. Local marina says I’m hitting the right RPMs, assuming I do not have anything mis-aligned. They believe 38 is my top speed.
Vikingstaff
Moderator
You can hit 38 mph with a 150 HP motor on a triton. You have a 300. Your marina is wrong. Very wrong. Wrong to the point I question their competence in this regard since they are off by 8-10 MPH at WOT for your motor and size boat.. You should easily be 46-48 MPH. My boat topped out at 44mph at WOT: 24’ S-series with SPS tritoon hull and 200HP Mercury Verado Pro motor. Your boat is heavier, but you have A LOT more HP and likely a better tritoon hull than me….
Pretty much everyone in the forum with that size R series tritoon with that size motor is in the 45-49 mph range once properly propped and dialed in when everything else is fine.
So again, your marina is not only wrong, they are not really in the correct ball part here.
IF you are fine with 38 MPH at WOT, stop reading here. Just stick with your setup.
IF you want to get the performance that 300HP motor is capable of getting, trouble shooting will be needed. Continue reading…
Here is my checklist based on the small amount of info you have provided so far:
1) You said pontoons are clean…so check that off the list.
2) I am assuming no leaks or water inside pontoons. Can you verify this fact?
3) You said “marina said RPM’s are right”, but they are CLEARLY wrong on boats capable speed, so I don’t trust their verdict on your RPM’s. Please share what your actual RPM’s are at WOT, lightly loaded (1-2 people, no gear, less than a half tank of gas), on fairly calm water with little to no breeze. With that number, members in here will know if you are ACTUALLY good with RPM’s at WOT. This will be helpful and necessary later in trying to dial in prop.
4) You said you have a 300HP motor. Which manufacturer and model? Important to know. For example Yamaha f300 or Yamaha VMAX 300, OR Mercury 300 or Mercury Verado Pro 300 or Mercury 300XT ….those specific differences mater later for propping.
5) What SPECIFIC model, material (aluminum or SS) and size (diameter & pitch) prop do you have? For example, I have an SS Enertia prop, 14.5 diameter(?) x 15pitch on my 200HP Mercury Verado Pro motor. Prop details matter A LOT.
6) How low or high is your motor mounted (which mounting hole)? Is your caviation plate below water line, above water line, or about at water line when at WOT? This can impact drag and ventilation of the motor, thus impacting performance.
My guess since you have clean pontoons, and assuming no pontoon leak, is you are not properly propped. Motor mount position could be impacting it too. So…if you want to get all you can out of it (or you just want to get a little bit more), then over time we can all help you trouble shoot and dial it in.
If you don’t want to do this, you can just roll with what you have so long as your RPM’s at WOT are not below the manufacturer recommended range. If RPM’s are either too high OR too low, it causes problems for your motor…