250 0r 300?

[TB21]

Looking at getting a new 21' Ally Bass boat in the near future and would like honest opinions on what power you'd put on it.

250XS , why or why not?

300XS , why or why not?

Gas milage difference between the two and does the 300 require hi-octane?

is there more maintenence with the 300?

Can't wait to get back into an Allison!!
Thnx, TB

 

[GotMyAlly]

I went with the 250XS but I had a huge internal struggle to make myself do it. I knew I'd always wonder what it was capable of with the 300XS, but in the end I decided to go with the 250XS. If i recall correctly, I think the price difference was about $3500. I thought that was steep for only a few HP. I believe the 300XS makes about 305 HP and the 250XS is about 275 HP.....so it's not exactly a 50 HP difference, more like 30. The real deciding factor though was reliability. There's a ton of 250's on the water and you almost never hear of them blowing up. I hear of a lot more 300's popping. And yes, the 300XS does require premium fuel. Maintenance wise.........no difference.

 

[GotMyAlly]

 

[Darth VMAX]

From what I have read and with Neals price #'s:

That equates to $1,167 per extra MPH (consensus seems to say there is "roughly" a 3 mph difference between the 250xs and 300xs).

 

[suicidealli]

Guys Tim is no stranger to ally's, he had an 02 with a 260, and NOS. Grew up racing karts on alcohol...
Tim if that speed is out of your blood, get the 250, if not you better find you a 300.
It takes everything a 300 has to hit 100. It is a lot of boat. A few claim a touch more, but not many..
You have some thinking to do brother......

Roy

 

[GotMyAlly]

It takes everything a 300 has to hit 100.

It also depends on which 21 you get. There's several mph difference between the prosport, 2+2, and the 2-seater.

And if a 300X was in the equation, that would be another story too. That's a whole different beast.....

 

[Darth VMAX]

The only one I have heard cracking trips is the Prosport.
Has a 2+2 done it as well?

 

[h2oskiier30]

If you're going to tournament fish in it, some trails have a 250 max hp rule.

 

[GotMyAlly]

The only one I have heard cracking trips is the Prosport.
Has a 2+2 done it as well?

In my experience, the speed difference between the prosport and the 2+2 is small. Denver has ran 90 in his 2+2 with a 225! Both have a considerable edge over the 2-seater though.

 

[whipper]

The 300 looks like it walks away from 4200- 4500 rpm up. So basicly they look neck and neck untill ya get close to being on the pad. After than the 300 according to the graph builds HP with a larger gap the rest of the way and would walk away from the 250. Up to 4200-4500 rpm theres only a 10 hp differance. With a 30 inch wheel that around 60-65mph. Pretty close untill ya have to start driving her.:wink The fuel cost running 87 over 91 is getting to be a bigger factor as years go on. That adds up with years of ownership for how many mph?

Is the SHO or Etech worth comparing to the XS on a 21?

 

[Alli-drenaline Rush]

JMHO, but I'd put premium in it even if the manufacturer calls for 87..... different refining processes for the two grades. Current plan is 100LL if ever I get a boat to put my motor on... It's all about quality control.... and what's $150/yr ($0.25/gal delta on 600 gal/yr) when you've sunk $15k into a motor???? And yes, I do understand that 100LL is more like $5/gal.....

There ain't no pockets in a shroud......

 

[msharp]

The horse power charts will fool ya ! True it dont show alot of difference in the two . BUT find a chart with the torque curve ! Believe me there is quite a bit ! That longer stroke will run off and hide from its little brother ! When the 250's fall of around 56 - 5800 the Stroker is getting its 2nd breath . It will PULL to its 6400 Limit. I had a 2005 250 and sold it and put a 2007 300 on in its place ! Was surprised in the difference in the two.

 

[TB21]

Thank for the opinions guys I appreciate it.

Roy, I really miss my old XB02 had alot of fun in it and it was stupid fast after all the port work and other tricks I did to it. I don't need to go as fast as I use to so Im leaning torward the 250 on the 21'er . If I can run 82-85 Tournament loaded I'd be very happy.
Oh and BTW Im well aware of the speed differences in between the 21'ers , I was at the Allison plant last fall and Darris told me the huge cockpit of the 2+2 allowed the trapped air to escape easier allowing a few more MPH.

Thnx again for the opinions.

 

[jimbob88]

I also want true findings with some of the torque monsters. The sho will spin up a bigger pitch. Will only have a 250 on my eventual 21 & want lots of stats please. my 21 will hafta seat at least 4 so I have two options. Prolly buy denvers so I dont hafta change my signature. Lol

 

[GotMyAlly]

The 250 will best 85 tournament loaded. I've run 89 tournament loaded in mine........

 

[TBuck2003]

I do not know how much "Stock" i put into that graph. If I am reading it correctly it is saying the 250 XS is making peak power at 5250-5500 ??? And the 300 XS is making peak @ 5750 ??? I have never propped out any of those motors to those specs. The 300XS 3.2 Stroker makes more Tq. for sure, but torque is not speed, it is getting the mass moving. I am not a Mercury engineer by any stretch but if 5500 was the best H.P. on Neals 21er he would have to be running 31 -32p. That is not going to be real good to fish out of tourney loaded. On the flip side the 250 HO ERude and the 250 SHO from Yamaha would be great options, except for one minor detail........ The GEARCASE. If you could run a sporty on those motors LOOK OUT. It is apparent BRP, and Yamaha did not want to get in the game of 90-100 mph bass boats, for warranty reasons. They want drive deep period. I like the 250 XS on the 21. Those two go together like Peanut butter n Jelly. My.02

 

[Darth VMAX]

As much as I like the 3.4L ETEC motors, their lower-unit sucks for boats like an Allison. Even with a LWP nose-cone the cross-section is MASSIVE. The SHO on the other hand has a good gearcase for HP boats. It can be GREAT with a couple of tweaks. Move the intakes to the bottom and install a fat-shaft and you are good to go.

On "regular" bass boats the 250 SHO and the 250 Pro xs are basically neck and neck in top speed. The SHO does out accelerate the Pro xs so in a sense the Pro xs won't catch it with all things being equal (which rarely ever is).

Is there any real performance difference between the 250xs and 250 Pro xs? I thought the main difference was lower-unit options.

 

[msharp]

Horspower makes MPH with out a doubt. But its usless if you cant get it moving. Torque is just as important when your talking about 1.62 gears and 30 and taller props on heavy boats . Ya just gota have them both ! More torque = tall gears and big wheels =

 

[GotMyAlly]

Is there any real performance difference between the 250xs and 250 Pro xs? I thought the main difference was lower-unit options.

Solid motor mounts and a light-weight cowling, which I think just amounts to omitted insulation -- it's still a tank.

 

[GotMyAlly]

The SHO on the other hand has a good gearcase for HP boats. It can be GREAT with a couple of tweaks. Move the intakes to the bottom and install a fat-shaft and you are good to go.

Isn't that HD propshaft alone a $1500 upgrade?