225 pro max vs. 2.5 vs. 300x
 

which one is the better choice for fun boating and poker runs

What kind of boat?

big cc 300x cat 2.5 or 225pm 110+

30 AMT

I would go with the 300xs. Speed of the 2.5s with the reliably of the 225s and oil injection. They should run well over 100mph.

225 Promax

I would say if you want fun and reliable go with the 225. You will pick up a couple miles per hour with the 2.5 and 300's but at a HUGE increase in price and also maintenence. Remember outboards unlike big blocks can run WOT all day long.

Jon

I agree Audiofn, except go with the 300x's, they should be about 4-$5,000 more per engine over the 225's, speed will increase greatly with an extra 100 h.p. per engine.

now mercury has a 5 year warrenty on some of there motors as long as there are not used for charter captin's or put on the race .. don't think they care about poker boats

just by chance i have it right here.. LOL

no merc race but

optimax 90-225hp 5year
4 stroke 40-225hp 5year

Here is my vote 300x
 

Pro Max 300X
Specifications
Propshaft Rated Horsepower (HP / kW): 300 / 224
Full Throttle RPM Range: 6100 - 6800
Cylinder/Configuration: V-6 (60 degree vee)
Displacement (CID/cc): 185 cu. In. (3032cc)
Bore & Stroke (in): 3.63 x 3.00
Bore & Stroke (mm): 92 x 76
Fuel Induction System: Electronic Fuel Injection
Ignition System: PCM 038 Digital Inductive
Charging System: 60-Amp (756 watt) with Voltage Regulator
Gear Ratio: 1.75:1 (TM) or (FM); 1.62:1 (SM)
Lubrication System: Electronic Mulitpoint
Fuel/Oil Ratio: Electronic Multipoint
Recommended Oil: Mercury Premium Plus (TC-W3)
Fuel Requirements: 91 octane (R + M/2) or 96 RON
Rotation: Left or Right Hand (SM)(FM) Right Hand (TM)
Shaft Length (inches): 20/25
Shaft Length (mm): 508/635
Weight (lbs / kg): 480/208 with 20" center section and Torque Master gearcase
Warranty: One-year limited warranty for recreational boating and three-year limited corrosion warranty. One-year limited Mercury Product Protection Plan available.
SmartCraft: Yes
Starting: Electric
Steering: Remote
Trim System: Power Trim




Features & Benefits

3.0L (185 CID) powerhead delivers unmatched power, performance, durability and reliability.

Electronic multipoint lubrication system delivers precise amounts of oil where and when it’s needed.

PCM 038 microprocessor provides maximum power and fuel economy.

Powerful 60-amp charging system operates electronic accessories without draining the battery.

Race-derived exhaust chest and tuner enhance power.

The SmartCraft™ Engine Guardian system monitors engine functions for early indications of problems that could lead to engine damage.

Torque Master and Fleet Master gearcases feature dual water pickups (mounted on the bullet and strut) for improved cooling, enhancing engine durability and overall performance.

Torque Master and Sport Master gearcases feature a heavy-duty propshaft for enhanced durability

Slingshot,

You have a pm.

An AMT was in a recent boating magazine with the 300's. With the 300's watch the porpoising, the article said it did it almost all the time except at top speed which was about 100mph. I would definitely install a tunnel tab, it gets rid of the porpoising and helps the boat plane more level.

The 2.5's should provide a better balance being lighter on the rear, which should fly more level. However, the 300x has the warranty, and is supposed to be more advanced than the 2.5's. I would go with the 300x and if the porpois was that bad, try a tunnel tab like macvtt said.

Where is T2x, I am pretty sure he is running 2.5's on his Skater

The 2.5's have a warranty, the "RACE" motor does not, and the only differnce between the two is the rev limiter in the stock motor is 7750 and the race is 8250....and does not have a low water psi sensor n the ECU.
The 300X motor is not all that reliable, you WILL use the warranty.
The new 225X is so far showing to be a good peice.

I vote for the 2.5's

RT

Out of curiosity, what's the biggest Merc O/B that doesn't require premium fuel? Probably not a concern if you're looking to build a 100 mph cat, but I was wondering for other reasons. (Center console.)
Don't mean to hijack the thread.

225HP 3.0 L

RT

I am.......But.....Here is my opinion....

If the cat is under 30 feet(28 Skater/30 AMT) go for the 300x's.... effective cruising speed will rise by about 10 mph......and top speed by about 5 over stock 2.5's.....
the 225's are considerably slower and rev less.......hence the increase in "dependability" (it is actually less self abuse)

If the boat is over 30 feet.....do not use outboards...... go for 525 hp's...and #6's.

Why?.....because everyone I know with a 32 and outboards...blows powerheads/lower units and center sections with awesome regularity......especially the 300x's.....

The reason?....I have no idea other than 32' cats are outboard eaters at 90+ mph in semi choppy water....The hulls apparently can take more than the engines will endure.

T2x

I AM LOOKING TO CRUISE AT 65-75

I didnt want to say what firewalker said, but I have heard some unreliable issues with the 300x, dont have any personal experience so not sure. I have heard rumor on another sight of a 4 stroke turbo charged OB motor by merc. Havent heard much since, so that might have been just a rumor.

225 Promax

Not a rumor- supposedly it will be debuted at the Miami show. Original specs were 250hp, but I had heard the dyno pull was 300hp.
It is supercharged at a very low boost level; possible growth to 400hp. Not sure of octane requirement.
This is Mercs baby- no Yamaha influences as in previous 4-strokes. The torque on this engine is reported to be enormous.
Jim

You have got to be kidding me!!! I can run wide open all day and never worry about it. I don't know of a 2.5 or 3L Merc that was meant to tool around all day at 3,500 RPM. As a matter of fact, they run better on the upper end. I'm not bumping the rev limiter but running at 6,000 RPM is average for me. The 300x is a hell of a motor. Tons of power and punch, 60amps of alternator power and it will crank every weekend. Keep water pressure in it and you can't go wrong. Sounds like a bunch of IO guys talking that have NEVER had an OB.

I think that's what he said . . .

Lee, You might want to re-read Jon's post.
I think you guy's are saying the same thing.

I guess I was just buzzing thru that. He did say they "can run all day". I was thinking "what the hell is he talking about" for a second there. Forgive me, I even had a vein on my forehead get big! Ha!

300X's do have explosion issues, much more so than the 2.5's, which incidentally also have a 60amp charging system and start every weekend.
Add that the 2.5 can be made A LOT more reliable, with modifications, with more power (yup you read correctly) and will give the 300X a run for the money... and when it gets rough, it will run and hide.

i'm thinking a par of 90's with four plated props and something to tie the tillers together with.. custom... lol

Well then CustomRigger101, buy Yamaha then.

J/K.. if i where you.. i'd buy the 225 opti's and run teh hell out of them for 5years.. and if anything went wrong drop it off at a merc shop and tell them to fix it.. but the motors have to be bought before april15

go with the warranteed motors........

T2x

Slingshot,

Did you call Tony?? He is really the best one to ask regarding 300's on the AMT, since he is the only one to have rigged one.

WILL CALL IN THE AM ON THURS

Cool, I gave him a heads up.

I was thinking about having him build me an AMT, and we have talked about the same issue.

Optimax 250 XS???
Use half the gas... Go just as fast!!!

Firewalker is dead on on all his comments.



Sling, you're asking the question in the wrong forum. Go to S&F and ask the question there... those guys know far more about these engines than 95% of the people on here.;)

Slingshot,

What boat, motor combo did you end up with?

I have got the 300x 2005 model... what is the maximum fuel pressure and can i fix after market hi pressure fuel pump