Back to the main site

Prop test data

jhill said:
I figured that the two slotted bolts would only be loosened and never be totally removed so can't go too far wrong .........but then there is "murphy's law" so I will take safety precautions when attempting. Maybe add a rope with pulley from above for additional control while performing operation. :rolleyes: Engine weighs like 500 # so should be easy to rig up from a beam, etc.
Click to expand...
Yes, caution is well advised! I have "adjusted" the height or our motors several times with the pontoons in very shallow water (have never owned a pontoon trailer) using blocks, prybars, etc. and the hydraulics of the motor itself, by myself. However, I would not recommend solo "shade tree" methods with anything more than 70-115 class motors. As you already know, planning is essential and two people that understand the mechanics of the job are strongly advised for larger motors. With that, the job isn't difficult and after you've done it once is pretty easy...just don't get complacent.
 
Just an update to anyone following.

I was able to finally swap out the dealer-provided 19p SWS for a 16p SWS to act as my spare. The 17p Q3 will continue to be the workhorse, but I datalogged the 16p anyhow to see what the results would be.

No surprise, performance slotted between the 17p Reliance and the 19p SWS. Top speed on the 16p was 46-47mph which was 2-3 mph short of the Q3. Efficiency was worse than both the 19p and the Q3 but better than the Reliance. Slip% could not better the Q3 anywhere in the RPM band. Holeshot and time to plane was very good, probably in the 3-4 second timeframe.

Overall I still believe the Yamaha SWS props are decent all-around performers, and the SDS hub makes for a much more pleasant experience if you perform a lot of gear changes. If I carried a lot of load or pulled tubes the SWS starts making more sense, but the Enertia/Q3 design with the swept rake and progressive pitch is the clear winner for my boat and use.




16p mph.jpg
16p mpg.jpg
16p slip.jpg
 
Really nice Work! Great data collection AND display. Your top speed with the SWS 16p is the same as our son gets with his 17p on a loaded 23' CC...don't have the top RPM, but no doubt its lower than you got (as would be expected). The Merc Q3 is easily the top choice for your rig and use. It might even be the top choice for running heavy and/or watersports too, but just in case you'll have the SWS 16p available to address any surprises.

Seems like I remember you hit 50 MPH with the Q3? Am I misremembering or was that under different conditions? Anyway, it's obvious why Merc gets top dollar for the high-tech Q3.
 
I changed from the stock Yamaha K 14/14 prop to the black diamond 14/13 this year. I was getting 5550 rpm and 22mph gps for my 20 foot svf with a Yammie F90. First time out this year with the black diamond and got 5820 rpm at wot and 26 mph. Loads were the same and not perfect conditions this year, so I’m pretty impressed with the BD
 
PB - I did hit 50mph, in perfect conditions (flat calm, 1 person, bow door open, hiding behind the windscreen ). 48-49 is what I can get in most conditions. I was hoping that the 16p would at least allow me to hit the rev limiter as I believe the Yamaha's like to be wrung out every now and again to keep them from making oil. But I can also send away my Q3 and have it labbed for a little more RPM if I feel like throwing more money at it.

Zeeman - Merc props for the win again! It seems they can get better performance than its competitors up and down the lineup. There's a reason they cost a little more.
 
Potomacbassin’ said:
... I was hoping that the 16p would at least allow me to hit the rev limiter as I believe the Yamaha's like to be wrung out every now and again to keep them from making oil. But I can also send away my Q3 and have it labbed for a little more RPM if I feel like throwing more money at it....
Click to expand...
Was wondering if the SWS 16p really topped out at 6000 RPM or if you cut off a the data, although that's about right as the 19p got to 5350. IF you are running with the motor full down, you might consider lifting it one hole before messing with the Q3. Interesting that the 16p gives pretty snappy acceleration without giving up much against either the 19p SWS or the Q3. I can see why the 19 SWS is popular on some of the 300 HP (+) CC's.
 
PartyBarge said:
Was wondering if the SWS 16p really topped out at 6000 RPM or if you cut off a the data, although that's about right as the 19p got to 5350. IF you are running with the motor full down, you might consider lifting it one hole before messing with the Q3. Interesting that the 16p gives pretty snappy acceleration without giving up much against either the 19p SWS or the Q3. I can see why the 19 SWS is popular on some of the 300 HP (+) CC's.
Click to expand...

Yep 6k was max RPM, was trimmed probably 50-60%. Motor is already at hole 3 so I think my next step is a jackplate so I can account for those times when I may want to whip the rear end around a little and not vent.

What was interesting was that the 16p speed was almost exact to the Q3 all the up to 4000 RPM, but the Q3 takes off after that. Not sure why that is.
 
Potomacbassin’ said:
What was interesting was that the 16p speed was almost exact to the Q3 all the up to 4000 RPM, but the Q3 takes off after that. Not sure why that is.
Click to expand...
That one is not too tough. The Enertia is oriented toward a higher performance/design goal. Combine that with the thinner blades using the "X7" alloy and the prop efficiency cap comes at a higher RPM. Your slip chart shows both the SWS 19p and 16p slip nearly level off ~4000 RPM, but the Q3 continues to improve all the way to WOT. Actually, Q3 really gets with the program starting about 3500 where the other two only have minor trends.

If I understand correctly, with the motor up to the third hole the SWS props may be negatively effected, but that is where the Q3 wants to live? Anyway, that's another reason to not tinker with the Q3 until you know it's worth the risk. Personally I'd have no use for a jackplate on a pontoon boat, but maybe you do? On second thought, no need to let bass people have all the fun with rooster tails at any speed.
 
Last edited:
PartyBarge said:
That one is not too tough. The Enertia is oriented toward a higher performance/design goal. Combine that with the thinner blades using the "X7" alloy and the prop efficiency cap comes at a higher RPM. Your slip chart shows both the SWS 19p and 16p slip nearly level off ~4000 RPM, but the Q3 continues to improve all the way to WOT. Actually, Q3 really gets with the program starting about 3500 where the other two only have minor trends.

If I understand correctly, with the motor up to the third hole the SWS props may be negatively effected, but that is where the Q3 wants to live? Anyway, that's another reason to not tinker with the Q3 until you know it's worth the risk. Personally I'd have no use for a jackplate on a pontoon boat, but maybe you do? On second though, no need to let bass people have all the fun with rooster tails at any speed.
Click to expand...
I get REAL shallow chasing bass at times. Other times I might be in a back creek with plenty of water but an outgoing tide leaves me with less than 2ft, so having the ability to jack up and plane out of some of those mud flats can be a trip saver. Trolling motor is a solution but sometimes the run is long so the big motor is better.
 
i purchased our 2021 23L sps+ with 250vmax in october from indiana, coming from an offshore performance boat capable of 72mph, during the sea trial i was happy to see 51mph gps @ 5400 w/ 2 people and 1/2 tank of gas. problem is i haven't seen 50's since getting it home to NY. boat has a lexor 15.5 x 17p prop. and now only hits 46-47 @ 5400. only thing i can see different is the prop now has some cavitation burn. the rpms seem the same but speed is down 3-4 mph. only added a few lbs ( anchor, life jackets, lines, and bumpers ) certainly not enough to lose 4 mph. can some cavitation burn cause this ? my rpms were always a bit low and have heard the lexors are commonly a bit larger in pitch than stamped and was considering going to a 16 or 17p enertia or mirage plus, would like to get the rpms up to about 5,900 w/ light load, but want to figure out the burn and speed problems before ruining a brand new merc. prop. motor is in lowest hole and i can trim all the the way up 3/4 before it porpoises... opinions / suggestions please ?? thanks in advance...

p.s. boat only had 28 hrs on it, now has 58...
 
Last edited:
Sea trial - did you have a tail wind or any current running with you that you don't have now? Pretty impressive to hit 51 with only 5400 RPM, many of us need to be in the high 5000's to get close to 50.

My view is if you can spin your prop the same RPM then the only way to lose speed is with your hull. A prop that loses its edge or has other imperfections will either speed up or slow down, but if you have the exact RPM something else is going on. The usual suspect is crud/algae on the toons, but also water in either a failed toon or sitting in the center storage locker and needs to be pumped out.

If you're losing RPM could be engine related - the VF250 requires 89 so confirm you're getting that at the pump.

As far as prop goes the Enertia is going to get you good hole shot and fuel efficiency with great speed. Mirage will have lower speed but better down low... maybe slightly better fuel efficiency at low RPM, similar at mid and worse at upper end vs Enertia. The Enertia should also allow you to move up a few holes without too much blow out on turns.
 
Thanks for the thoughts, Toons are squeeky clean. trial was on a reservoir and ran same speed both directions. I always run the bilge and will check for water. The lexor has a huge amount of cup and was a great performer initially. Wonder why im getting cavitation burn ?
 
Last edited:
chris288 said:
i purchased our 2021 23L sps+ with 250vmax in october from indiana, coming from an offshore performance boat capable of 72mph, during the sea trial i was happy to see 51mph gps @ 5400 w/ 2 people and 1/2 tank of gas. problem is i haven't seen 50's since getting it home to NY. boat has a lexor 15.5 x 17p prop. and now only hits 46-47 @ 5400. only thing i can see different is the prop now has some cavitation burn. the rpms seem the same but speed is down 3-4 mph. only added a few lbs ( anchor, life jackets, lines, and bumpers ) certainly not enough to lose 4 mph. can some cavitation burn cause this ? my rpms were always a bit low and have heard the lexors are commonly a bit larger in pitch than stamped and was considering going to a 16 or 17p enertia or mirage plus, would like to get the rpms up to about 5,900 w/ light load, but want to figure out the burn and speed problems before ruining a brand new merc. prop. motor is in lowest hole and i can trim all the the way up 3/4 before it porpoises... opinions / suggestions please ?? thanks in advance...

p.s. boat only had 28 hrs on it, now has 58...
Click to expand...

I ripped through some Yamaha Performance Bulletins and most 250 VMax testing was done with their SWII series props.
I wasn't able to look at too many YPBs since Ive got limited time right now, so you may want to dig in further.
15.75x17 seems to show the highest top speed, but there are so many variables.
yamahaoutboards.com

VF250LA on Manitou 23 Encore SHP Performance - Yamaha Outboards

Find detailed specs and performance information for the Yamaha VF250LA outboard motor paired with a Manitou 23 Encore SHP boat.
yamahaoutboards.com yamahaoutboards.com

Not saying that a different prop will ultimately solve your hunger for more speed, but it'll at least give you a starting point of gathering comparative data to make a decision if it will be worth pursuing or not.
 
Last edited:
Any disadvantage to raising the motor up 1 hole besides the possibility of sharp turning ability ?
 
chris288 said:
Any disadvantage to raising the motor up 1 hole besides the possibility of sharp turning ability ?
Click to expand...

No. You're raising the possibility of ventilating the prop the higher you go, but up to that point any additional drag removed is a good thing. Keep in mind if you have a larger diameter prop that may limit you to how high you raise it vs a lower diameter prop (ie Mirage vs Enertia).
 
riased the motor one hole and tried tried it yesterday, no real takeaways except i can run with less trim now, was too windy and rough to try high speed runs. i have a 17p enertia comming this week, wondering if someone can point me in the right direction for the correct hub kit i need to use on my 250 vmax ?
 
chris288 said:
riased the motor one hole and tried tried it yesterday, no real takeaways except i can run with less trim now, was too windy and rough to try high speed runs. i have a 17p enertia comming this week, wondering if someone can point me in the right direction for the correct hub kit i need to use on my 250 vmax ?
Click to expand...

Probably a Flo-Torq. Maybe inquire with PropGods?
 
ugh, i'm back here again after last season making peace with my prop. I'm running a 24 LSB with the SPS+ toons, and a vmax 250. running a 15.75x15 right now that seems good for normal use. it cavitates a bit when turning hard at speed, especially when tubing, unless i trim down quite a bit. Motor is mounted as low as it goes. i hit 45 with clean toons, 2 of us and half tank of fuel...

but yesterday, i was tubing with a lighter tube load than usual, but heavier passenger load, and everyone in the back... man it was a real drag, literally and figuratively. some of my numbers had my slip between 20-40%... It might be a more regular load out for me. should I be repropping? WOT was like 5350, and 36mph...

Last year i was toying with a 4 blade, i'm guessing that would help... i wish i could get a box of props to mess with, lol. Not that my passengers would be too excited doing data collection all day while i swap props... ;)

Anyone know anything about Michigan Wheel Props?

Outboard Propellers | High Performance Boat Props

Michigan Wheel Outboard Propellers are designed for optimizing performance. They are made with high grade metal alloy for all wake, fishing & cruising boats.
www.miwheel.com www.miwheel.com
 
A box of props to play with would be great wouldn’t it!?! It’s what keeps me from trying to dial mine back in post-Sea Legs, and post major repairs. It does run and handle great, but based on RPM’s alone, I know there is now room to dial in a little better.
 
Last edited:
i would try a 4 blade solas, they are good performers and wont break the bank, you will lose 2-3 on top, but it shouldreduce your slip % greatly.
 
You must log in or register to reply here.
Back
Top