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MERCURY MARINE
2.5hp & 3.5hp 4-Stroke Outboards

Mercury Marine’s 4-stroke technology consumes 40% less fuel than 2-stroke models for extraordinary value and savings

Engines surpass California Air Resources Board (CARB) 3-Star Rating, making them some of the cleanest running on the market-with 91% less emissions than traditional 2-stroke outboards!

The inherent 4-stroke characteristics of ultra-quiet, smoke-free operation, plus smooth idling and running make these engines a natural choice whether you’re trolling for fish or out just for fun. Clean running 4-stroke engines from 2.5 to 20hp have a CARB three-star, ultra-low emissions rating. The decompression system and electronic CD ignition design ensure an easy, reliable start. One-stage over-rev protection and low oil pressure warning system provide extra peace of mind. Exclusive multifunction tiller handle on the 8hp and 9.9hp models features shift, steering, throttle, throttle friction, and stop controls for convenient one-hand operation. Available in manual-tilt, gas-assist and power-trim. All models are sold with a propeller.

  • Engine Type: 4-stroke
  • Features: 4-stroke technology-quiet, environmentally friendly, 40% more fuel efficient than comparable 2-stroke engines, smooth running/exceptional idling
  • Exhaust: Above prop
  • Start: Manual, with decompression system
  • Steering Type: Tiller (2.5hp-6hp), tiller or remote (8hp and higher)
  • For U.S. shipment ONLY

2.5hp & 3.5hp 4-Stroke Outboards

  • Patented one-piece integrated cylinderblock design provides added reliability by eliminating gaskets and fasteners and makes the powerhead much more compact and lightweight
  • Check oil level without removing the cowling with convenient, easy-to-view sight gauge
  • This engine delivers maximum performance with the largest displacement in the 2.5 hp category
  • A twist-grip throttle and 360-degree steering make it easy to use
  • Steering Type: Tiller with 360° turning
  • Gearing: F-N, 2.15:1
  • Trim Positions: 4
  • Tank Type: Integral fuel tank (gal / L)
  • Tank Capacity: 0.3gal.

Note: These Mercury outboards have 4-stroke engines and, like virtually all 4-stroke engines, depend on oil in their crankcases for lubrication. To prevent the oil from leaking during transport, the engines are not shipped with oil in their crankcases. You must put the correct amount and grade of oil in the crankcase prior to the first use or you will cause extensive damage to your engine, which is not covered by your engine’s warranty. Please read the owner’s manual for more information.

For U.S. shipment ONLY.

Product Models
Description WM Model # MFG Part # Availability Price Quantity  
2.5hp 4-Stroke Outboard, 41lb., 15" Shaft Length, F-N Gearing, 0.3 Gallon Tank 7754849 1F02201EK
In stock online.

$899.00

Add to My List
3.5hp 4-Stroke Outboard, 41lb., 15" Shaft Length, F-N Gearing, 0.3 Gallon Tank 7754856 1F03201EK
In stock online.

$1,069.00

Add to My List
3.5hp 4-Stroke Outboard, 43lb., 20" Shaft Length, F-N Gearing, 0.3 Gallon Tank 7754864 1F03211EK
Ships when available.

$1,089.00

Add to My List

Mercury Marine’s 4-stroke technology consumes 40% less fuel than 2-stroke models for extraordinary value and savings

Engines surpass California Air Resources Board (CARB) 3-Star Rating, making them some of the cleanest running on the market-with 91% less emissions than traditional 2-stroke outboards!

The inherent 4-stroke characteristics of ultra-quiet, smoke-free operation, plus smooth idling and running make these engines a natural choice whether you’re trolling for fish or out just for fun. Clean running 4-stroke engines from 2.5 to 20hp have a CARB three-star, ultra-low emissions rating. The decompression system and electronic CD ignition design ensure an easy, reliable start. One-stage over-rev protection and low oil pressure warning system provide extra peace of mind. Exclusive multifunction tiller handle on the 8hp and 9.9hp models features shift, steering, throttle, throttle friction, and stop controls for convenient one-hand operation. Available in manual-tilt, gas-assist and power-trim. All models are sold with a propeller.

  • Engine Type: 4-stroke
  • Features: 4-stroke technology-quiet, environmentally friendly, 40% more fuel efficient than comparable 2-stroke engines, smooth running/exceptional idling
  • Exhaust: Above prop
  • Start: Manual, with decompression system
  • Steering Type: Tiller (2.5hp-6hp), tiller or remote (8hp and higher)
  • For U.S. shipment ONLY

2.5hp & 3.5hp 4-Stroke Outboards

  • Patented one-piece integrated cylinderblock design provides added reliability by eliminating gaskets and fasteners and makes the powerhead much more compact and lightweight
  • Check oil level without removing the cowling with convenient, easy-to-view sight gauge
  • This engine delivers maximum performance with the largest displacement in the 2.5 hp category
  • A twist-grip throttle and 360-degree steering make it easy to use
  • Steering Type: Tiller with 360° turning
  • Gearing: F-N, 2.15:1
  • Trim Positions: 4
  • Tank Type: Integral fuel tank (gal / L)
  • Tank Capacity: 0.3gal.

Note: These Mercury outboards have 4-stroke engines and, like virtually all 4-stroke engines, depend on oil in their crankcases for lubrication. To prevent the oil from leaking during transport, the engines are not shipped with oil in their crankcases. You must put the correct amount and grade of oil in the crankcase prior to the first use or you will cause extensive damage to your engine, which is not covered by your engine’s warranty. Please read the owner’s manual for more information.

For U.S. shipment ONLY.

Specs

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REVIEW SNAPSHOT®

by PowerReviews
Mercury Marine2.5hp & 3.5hp 4-Stroke Outboards
 
2.4

(based on 51 reviews)

Ratings Distribution

  • 5 Stars

     

    (11)

  • 4 Stars

     

    (8)

  • 3 Stars

     

    (1)

  • 2 Stars

     

    (2)

  • 1 Stars

     

    (29)

39%

of respondents would recommend this to a friend.

Pros

  • Compact (22)
  • Easy to use (17)
  • Easy storage (13)
  • Safe (5)
  • Waterproof (4)

Cons

  • Unreliable (24)

Best Uses

  • Boating / sailing (21)
  • Kayak / canoe / rafting (3)
  • Personal watercraft (3)
    • Reviewer Profile:
    • Advanced (25), Casual/ recreational (20), Professional (6)
    • Was this a gift?:
    • No (14)

Most Liked Positive Review

 

Use fresh fuel!

I needed a replacement for our 15 year old Mercury 9.9 that weighed a ton and was a lot of work to deal with moving the tender around. We decided our racing days were...Read complete review

I needed a replacement for our 15 year old Mercury 9.9 that weighed a ton and was a lot of work to deal with moving the tender around. We decided our racing days were behind us so got this MUCH lighter 3.5 Mercury (Tohatsu) for the Zodiac tender. It started right up the day I purchased it and only took me a few outings to realize that FRESH FUEL is paramount to this motor running fine. I allowed the fuel to sit in the tank for a few months and when it went to start, it was ugly. Eventually pulled the carb (very simple two bolt), cleaned it and added FRESH FUEL. Started right up, idled smooth and drove away nicely. No other problems in two years. The fuel tank is only .3 gallons which is about an hour or so at full throttle. I carry a small amount of "spare" fuel to get me back in case I run out. Happened once. Added the fuel and started right back up on the second pull.

Overall, it's a really nice, light motor and will push along 4 adults in the Zodiac with no problems.

VS

Most Liked Negative Review

 

An Awful Motor

I have owned many boats and many outboards. This is the most unreliable motor I have ever had. Bought it new a month ago (August 2013). Didn't notice until later the motor...Read complete review

I have owned many boats and many outboards. This is the most unreliable motor I have ever had. Bought it new a month ago (August 2013). Didn't notice until later the motor was actuallly manufactured in 2011 which should tell you something about how many they sell.

The motor has a mind of it's own. It will just quit and be impossible to restart. Yesterday I was out with my grandson and the motor died 2 miles from our dock. Tried to restart for half an hour. Finally got a friendly tow from the Coast Guard Auxiliary

Reviewed by 51 customers

Displaying reviews 1-10

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(1 of 1 customers found this review helpful)

 
1.0

Not sure yet, its broke & West Marine won't give me a refund

By Benz

from San Diego/Pt Loma

About Me Casual/ Recreational

Verified Buyer

Comments about 2.5hp & 3.5hp 4-Stroke Outboards:

Got it on the dingy, but it wouldn't start. Finally after many, many tries, it started but ran real hot, the water pump wasn't working properly I think. Also the trim stop didn't work. Took it back to West Marine for a refund or store credit and they refused, said I need to take it for warranty work down in Chula Vista. West Marine's "no hassle" return policy is a joke. The motor - which was brand new but the floor model - may be good once I get it fixed or replaced, but I'm steering clear of West Marine unless I absolutely have to go in there

  • Was this a gift?:
  • No

(1 of 1 customers found this review helpful)

 
1.0

Would never buy this engine again!

By AngryBill

from Cape Cod

About Me Advanced

Verified Reviewer

Pros

    Cons

    • Unreliable

    Best Uses

      Comments about 2.5hp & 3.5hp 4-Stroke Outboards:

      Consistant problems, constantly cleaning carb, changing plugs, fixing leaking fuel line, cleaning points, shift breaks, on/off fuel switch breaks, ect. Worst engine ever, even as a mechanic I have reached my limits.

      • Was this a gift?:
      • No

      (4 of 4 customers found this review helpful)

       
      2.0

      Would not buy again

      By Sean D

      from Irvine, CA

      About Me Casual/ Recreational

      Verified Reviewer

      Pros

      • Compact Design
      • Easy Storage

      Cons

      • Unreliable

      Best Uses

      • Boating

      Comments about 2.5hp & 3.5hp 4-Stroke Outboards:

      Good thing is the 3.5hp is small and light. When I got it, I sat on it for about a year before ever firing it up. When it wouldn't fire up, took it to a Mercury dealer who tried cleaning the carb, but later found it was a manufacturing defect in the carb. Merc wouldn't warranty it because it was part of the fuel system. Had to replace the carb on my own dollar. West Marine does not accept returns on these.

      • Was this a gift?:
      • No

      (3 of 3 customers found this review helpful)

       
      5.0

      Great little outboard

      By SI2

      from Palmetto, Fl

      About Me Casual/ Recreational

      Verified Buyer

      Pros

      • Compact Design
      • Easy Storage
      • Easy To Use
      • Safe

      Cons

        Best Uses

        • Boating

        Comments about 2.5hp & 3.5hp 4-Stroke Outboards:

        A tank of gas lasts about 40 minutes with throttle fully open

        • Was this a gift?:
        • No

        (2 of 3 customers found this review helpful)

         
        5.0

        The replacement fromn Mercury is AWESOME

        By happy Mercury client

        from Honolulu, Hawaii

        About Me Casual/ Recreational

        Verified Reviewer

        Pros

        • Compact Design
        • Easy To Use
        • Quiet
        • Waterproof

        Cons

          Best Uses

          • Dinghy

          Comments about 2.5hp & 3.5hp 4-Stroke Outboards:

          The replacement that Mercury sent - has been perfect - started right up - super quiet - no issues.
          They stand behind their product and it is FANTASTIC!
          Earned a customer for life.

          • Was this a gift?:
          • Yes

          (3 of 3 customers found this review helpful)

           
          4.0

          I would buy this product again.

          By Noa

          from Dinner Key Marina

          About Me Advanced

          Verified Buyer

          Pros

          • Compact Design
          • Easy Storage
          • Easy To Use
          • Safe
          • Waterproof

          Cons

            Best Uses

            • Personal Watercraft

            Comments about 2.5hp & 3.5hp 4-Stroke Outboards:

            A lot of my friends don't care for the 4stroke engine. I haven't owned my unit but a few weeks however I am still breaking it in but to date I am very much satisfied. It requires adjusting of the choke before a smooth ideal not sure how long it will take to reach a one pull start. Other than that it is a good strong little motor. Faster and stronger then my 2 stroke marina.

            Service and delivery comments:

            My engine was special delivered free and on time. Thank you west marine! I understand that is not normal procedure.

            • Was this a gift?:
            • No

            (6 of 6 customers found this review helpful)

             
            4.0

            Use fresh fuel!

            By Seahog

            from SW Florida

            About Me Advanced

            Verified Reviewer

            Pros

            • Compact Design
            • Easy Storage

            Cons

              Best Uses

              • Boating

              Comments about 2.5hp & 3.5hp 4-Stroke Outboards:

              I needed a replacement for our 15 year old Mercury 9.9 that weighed a ton and was a lot of work to deal with moving the tender around. We decided our racing days were behind us so got this MUCH lighter 3.5 Mercury (Tohatsu) for the Zodiac tender. It started right up the day I purchased it and only took me a few outings to realize that FRESH FUEL is paramount to this motor running fine. I allowed the fuel to sit in the tank for a few months and when it went to start, it was ugly. Eventually pulled the carb (very simple two bolt), cleaned it and added FRESH FUEL. Started right up, idled smooth and drove away nicely. No other problems in two years. The fuel tank is only .3 gallons which is about an hour or so at full throttle. I carry a small amount of "spare" fuel to get me back in case I run out. Happened once. Added the fuel and started right back up on the second pull.

              Overall, it's a really nice, light motor and will push along 4 adults in the Zodiac with no problems.

              Service and delivery comments:

              Started on the first pull when brand new and two years later still does. I do believe it's about time for an impeller now.

              • Was this a gift?:
              • No

              (4 of 4 customers found this review helpful)

               
              1.0

              3.5 is unreliable

              By windrider rider

              from marina del rey CA

              About Me Casual/ Recreational

              Pros

              • Compact Design

              Cons

              • Unreliable

              Best Uses

                Comments about 2.5hp & 3.5hp 4-Stroke Outboards:

                Since 2012, I have used two different 3.5 engines to power a 300 pound windrider 17 trimaran upwind or in calm. In both engines, extended periods of use were a problem. it would stall after 30 minutes, but I try to run it 60 to 75 minutes. After it cools down it runs again for awhile. This problem could not be detected in a tank test because it was under less load, so I wasted lots of time trying to convince the dealer from whom I purchased it that it was defective. The problem was fixed for a couple of years by a custom installed fuel pump by a different dealer. When I had engine serviced by the dealer, from whom I purchased it, it began stalling in first few minutes. A different dealer cleaned the carb a second time and it was at least better in the tank. I have always been careful to only use new fuel. this dealer told me that the 3.5's carb is VERY sensitive and finicky. problems with the 3.5 are much more common he says than problems with the 2.5./ When it runs, it is relatively quiet and strong.

                • Was this a gift?:
                • No

                (2 of 2 customers found this review helpful)

                 
                5.0

                Great little motor!

                By Steve

                from San Diego, CA

                About Me Casual/ Recreational

                Verified Buyer

                Pros

                • Compact Design
                • Easy To Use

                Cons

                  Best Uses

                  • Boating
                  • Personal Watercraft

                  Comments about 2.5hp & 3.5hp 4-Stroke Outboards:

                  Great little motor. Runs well and is smoke free.

                  • Was this a gift?:
                  • No

                  (6 of 6 customers found this review helpful)

                   
                  1.0

                  Bad first impression. Zero stars!

                  By Jim

                  from Hudson, MA

                  About Me Casual/ Recreational

                  Verified Buyer

                  Pros

                    Cons

                    • Unreliable

                    Best Uses

                    • Boating

                    Comments about 2.5hp & 3.5hp 4-Stroke Outboards:

                    Engine starts hard and reliably stalls when accelerating to speeds above idle unless you adjust the choke and throttle at the same time and then only sometimes doesn't stall. When cruising, it runs okay. Air vent on gas tank can get too tight to open without tools not normally kept on a small boat. VERY disappointed in this motor. It is three hours into a ten hour break in process. If it does not improve, it is going to make a good, albeit expensive anchor. I have a one cylinder four cycle lawnmower that starts the first pull every time and doesn't stall. This engine should be taken off the market until Mercury can figure out how to make it run.

                    Service and delivery comments:

                    Delivery was prompt.

                    • Was this a gift?:
                    • No

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