The 1.75 gears are going to kill the 300r on a light fast boatOriginally Posted by Danible70
The 1.75 gears are going to kill the 300r on a light fast boat
It has 23 hrs.
I’m thinkin the same thing....
BULLET 20 XRD/250 Merc Sport XS
www.ncboatguy.com
The 250 Pro XS and 250R are the same outboard besides the latter having a different lower unit, stiffer mounts and oil cooler I believe. The 250 and 300hp v8s use the same throttle body(175-225hp v6&v8s use the same), but the 300R has shorter intake runners and different cam profile so I'm pretty sure it trades a little low end power for top end with a higher 6400rpm limiter as well as makes more than a regular 300hp Pro XS.
I have compared almost every part number from the Pro XS and the 250R. They are far from the same motor. There are a large number of components that are different. Is the 250R faster, I can't say but I have seen people complaining they can't get 6000 out of a 24P Fury in the same boat/ProXS, and I am moving to a 25P because I am all over 6200 with the 250R.
Mercury Racing said this on one of their blogs:
"The 250R and 250 ProXS share the same powerhead and midsection. The only difference is the gearcase. The ProXS is fitted with the Torque Master. The 250R comes equipped with the surface piercing Sport Master. The Sport Master is designed for use on lighter weight hulls with natural bow lift and capable of speeds in the low 80s. If your boat needs power trim to raise the bow – go with the ProXS. You are going to love the enhanced bottom end torque and acceleration!"
Look up the mercury catalog. It's good info if your bored. There are alot the same but many more differences than people realize. Again not sure if performance is different, maybe these help with endurance and longevity in the race application.
I think that is more do to their driving/setup abilities, as I drove a 920 (same hull you have) w/ 250 Pro XS 4T to 76+ @6100+ RPM with a stock 24 Fury3. And that was the only time I aired it out so I know there is more there with more setup time. Not saying you are wrong as the 250R might certainly make more but as of yet no one knows how much for sure.
It would be nice if one of the shops with a dyno could run a Pro XS and 250R back to back so we could see the differences!
Last edited by J Risco; 09-21-2018 at 03:53 PM.
2021 Phoenix 920 Elite / SHO 250
Bullet 21XD / 250 XB (Gone to a great home in LA)
"There is no such thing as a bad day fishing!"
I have looked at them on the link below, what specifically have you found different between them than what has been mentioned?
https://www.mercurymarine.com/en/us/.../parts-catalog
A back to back dyno between the two would be the best comparison, though I don't expect much of a variance being they use the same throttle body, intake, heads, cams, pistons, and exhaust as well as the same fuel requirements. So besides a slight machining tolerance difference or dyno error I expect they both push the 10% rule and put out ~275hp with the same rpm limit. Where as the 300R is probably pushing the envelope with ~330hp and the 300 Pro XS slightly less though probably a little more than the advertised 300hp if I had to guess.
Last edited by Wheelman; 09-21-2018 at 11:23 PM.
While I mostly agree with you, remember the SHO 200, 225, and 250 all use the same throttle body, intake, heads, cams, pistons, and exhaust as well... only difference is in the ECU.
Do the 250 Pro XS And 250R come with the exact same part number ECU? (I havent had the time to look thru part numbers so that is an honest question) Cause if there is a difference it could be found there. The 10% rule is what I thought of as well, as they are likely pushing it with the Pro XS so there wouldnt be much room for the 250R to make more.
2021 Phoenix 920 Elite / SHO 250
Bullet 21XD / 250 XB (Gone to a great home in LA)
"There is no such thing as a bad day fishing!"
ECU is different as well as a couple of parts in the exhaust, intake side of the head. The long block part number is different. And a few others. I haven't made a list but if you have the link, have a look. Again, I am not saying the 250R has more power. I'm just saying it more different than commonly known.
I should probably note, I hope you guys dont guy one. That's my official review.
That right there could make all the difference. Im wondering if maybe it makes more midrange (therefore not pushing the 10% rule over) which could allow it to spin up easier and possibly turn a slightly stiffer prop... would be easy to accomplish with the 4T too, as most of the newer 4T engines are overbuilt and have untapped potential.
2021 Phoenix 920 Elite / SHO 250
Bullet 21XD / 250 XB (Gone to a great home in LA)
"There is no such thing as a bad day fishing!"
Guys- they're not the exact same engine. Some have more differences than others, but there are definitely differences.
Given the HUNDRED + 250hp Fourstroke models, it's going to be easier to just order what you need/want.
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
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