I am going from a 12 sho 250 to a 23 proxs 250 and was told i would be disappointed by the loss i will see in performance by a very experienced engine/prop specialist. Has anyone experienced this? Thanks
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I am going from a 12 sho 250 to a 23 proxs 250 and was told i would be disappointed by the loss i will see in performance by a very experienced engine/prop specialist. Has anyone experienced this? Thanks
I can't speak on that, but I've got a buddy with a back country 201 with a newish 250 PRO XS......his boat is fast.......faster than mine and I have the same hull, a little different cap and 300R.......I picked up 13 mph going from a 250 SHO to a 300R on a Lake + Bay backwater. The 300R has a lot more torque and better fuel economy also.
Get it set up correctly I don't think you will be disappointed!
4 stroke technology is here to stay. We will always have naysayers when older technology is replaced.
Is his the 4 stroke? Wish i could go 300 but can'tQuote:
Originally Posted by Capt James
That is where i am lost. Mark said a 21 tempest plus would be best for my 2000+' of elevation and z521Quote:
Originally Posted by 5keepers2
Coming from an sho 4 stroke, that doesn't matter to me. To the question, is the new xs a disappointment compared to the sho?Quote:
Originally Posted by mikesxpress
Maybe if your SHO was flashed, but HP to HP Mercury should be stronger with better LU.Quote:
Originally Posted by mram10us
^ This
I admit I'm a 250 sho owner but I've had Mercs and love them as well. One thing that I just can't wrap my head around is this: If HP is HP and 250HP Yamaha SHO = 250HP Merc ProXs (non racing) then why do so many people have to drop several pitches in prop to run the new Merc? To me having to drop in pitch says the engine doesn't have the needed torque to run the higher pitch prop or at least the engine doesn't have the low end grunt. My FX21 jumps on plane with a 25P Yamaha T1 prop. I see were many people with similar hulls as mine (non go-fast hulls like Bullet, Stroker) have to drop to 23P or some even report 22P. I have a hard time understanding this. Some will say that the Merc has a higher WOT rpm than the SHO so the lower pitch prop is needed but again power should be power and if you have 250HP available and the lower unit gear ratios are the same then why the need to drop so much in prop pitch? Someone educate me. I'm really wanting to understand the science of this. Not bashing the Merc 4 strokes at all.Quote:
Originally Posted by JAZII
A lot of this has to do with the gearing of the LU and the WOT RPM. Each motor is different. For example, I have owned 150 Optimax motors. One had a LU of 2.00 gears and the other 1.87. The 2.0 needed a 25 Tempest and the 1.87 needed a 23 Tempest. Unless everything is the same, you really cannot compare props.Quote:
Originally Posted by ChooChooSnakeMan
It is flashed :)Quote:
Originally Posted by JAZII
You're not going to have the same hp on a stock merc 250 vs your flashed SHO, but you should be able to run 22 or 23 Fury at 2000 feet. I went from a stock 250 Sho to a new ProXS 250 and haven't been disappointed on a BassCat. I'm running a 23 Fury at 2400 feet altitude on a Cougar.
Great to hear. ThanksQuote:
Originally Posted by mike464
Yes a 4 stroke 250 PRO XS. The PRO XS's have A LOT more torque than the 2 strokes. They like bigger diameter props.......Mine is 2+ mph faster with a bravo XS over a pro max....... The Mercury's have a lot more balls than the SHO's.......I had an SHO and it felt anemic in comparison.Quote:
Originally Posted by mram10us
The newer merc lower units have alot less slip than the old ones. This allows for a smaller pitch prop to achieve the same speed at the same rpm as a bigger prop with more slip. Also allows for better holeshot with a smaller pitch, and as stated, a 6200 rpm max on the merc. The fury prop that most are running also is a bit stiff, a 24 is more like a 25 etcQuote:
Originally Posted by ChooChooSnakeMan
Quote:
Originally Posted by Jasonrs
^^^^ Why Thank You, Jason! Dead-nuts-accurate explanation.
What sho did you have?Quote:
Originally Posted by Capt James
A stock 2015 with 311 hours when I sold it, 20".Quote:
Originally Posted by mram10us
I have had four. The first one seemed good. The rest have all felt weak.
Thanks for the explanation, I can see how prop slip plays into the equation, good explanation in simple terms!Quote:
Originally Posted by Jasonrs
I will add that most are trying run to large of pitch and are not getting to the recommended RPM for that motor. Also running them to high and excessive trim.
Bought my Merc 250 in 2019, and have 300 hours on her....best motor I have ever owned, and I have owned a few over 60 years. On this big Delta, takes 24 maps to cover it, it is never a 20 minute run....you will put hours on an engine.
And then add to that the quad bracket to accommodate 2@ 12" graphs, 2@ 15" graphs, an Ultrex, and at least one point-GPS system hanging on the bow.
Now that we're looking for contact lenses on the bottom of the lake... we'll switch from AGM's to Lithiums (times 3 or 4), and make the handiest lockers the ones under the front deck.
Ok... I'm picking fun, but I swear, I've seen ^^^^ that boat more times than I can count!
Great to hear. Any shos to compare it to or xs?Quote:
Originally Posted by lakebouef5
Ive driven several boats with 250 pro XS and 250 SHO. The Yamaha really shines in midrange instant punch imo. Both have great hole shot. pro XS probably can get a little higher top end.
My next engine will be a 300R. Merc got the 300R right!
I went from a stock 250 SHO and my best was 67 mph ONCE, but consistently 65 mph yes mid range was great but motor kind of fell on it's face from 5200-5900 rpms. To a 300 R and consistently 79 mph. Tons of power throughout the rpm band.Quote:
Originally Posted by mram10us
Not sure how a 300r compares to a 250xs. Thoughts?Quote:
Originally Posted by Capt James
Good info. Thank youQuote:
Originally Posted by DJ Murda
Got 3 hours on the new 250xs. Tomorrow i will get a bit of speed testing.
I repowered my 2002 520vx with a new proXS 250 four stroke just a month ago and this hull loves it. Rated for 225 but is 20’9” and not much weight difference in motors. Running a 23 pitch tempest plus with a great hole shot and midrange acceleration to match. I’ve not seen top end yet but have hit 72 with not much trim. I have 15 hours on it now. I’m almost glad my old optimax blew up. Lol
Oh man, the HP police are going to be coming. Some guys on here are convinced you'll run into a schoolbus full of children if you run over the hull rating.Quote:
Originally Posted by local16
Bring it….Quote:
Originally Posted by Mcjenson
Got another few hours on it and did the "wot for up to 5 minutes" a few times. Only saw 6k rpm with 67.1mph. Need to figure out the sweet spot for the bobs and motor. Tournament weight