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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)
  • Warranty: Five years
  • 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.

Customer Reviews
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 1F02201HK
In stock online.

$900.00

3.5hp 4-Stroke Outboard, 41lb., 15" Shaft Length, F-N Gearing, 0.3 Gallon Tank 7754856 1F03201HK
In stock online.

$1,049.00

3.5hp 4-Stroke Outboard, 43lb., 20" Shaft Length, F-N Gearing, 0.3 Gallon Tank 7754864 1F03211HK
In stock online.

$1,069.00

Product Description

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)
  • Warranty: Five years
  • 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.

West Advisor

The West Advisor articles have answered boaters' questions and provided solutions to boating problems for more than 20 years. West Marine has compiled one of the Web's most comprehensive collections of technical boating information articles.

REVIEW SNAPSHOT®

by PowerReviews
Mercury Marine2.5hp & 3.5hp 4 Stroke Outboards
 
1.7

(based on 32 reviews)

Ratings Distribution

  • 5 Stars

     

    (2)

  • 4 Stars

     

    (4)

  • 3 Stars

     

    (1)

  • 2 Stars

     

    (1)

  • 1 Stars

     

    (24)

22%

of respondents would recommend this to a friend.

Pros

  • Compact (10)
  • Easy storage (6)
  • Easy to use (6)

Cons

  • Unreliable (19)

Best Uses

  • Boating / sailing (11)
    • Reviewer Profile:
    • Advanced (18), Casual/ recreational (10), Professional (4)

Most Liked Positive Review

 

a little gem

2.5 hp runs one hour at full throttle on a tank (0.3 gal.) of fuel.
perfect for trolling or moderate travel with a light boat.
light weight and easy to...Read complete review

2.5 hp runs one hour at full throttle on a tank (0.3 gal.) of fuel.
perfect for trolling or moderate travel with a light boat.
light weight and easy to move.
owners manual needs improvement - diagrams and photos.

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 32 customers

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1.0

Junk

By shadman

from Dallas, TX

About Me Advanced

Pros

    Cons

      Best Uses

        Comments about Mercury Marine 2.5hp & 3.5hp 4 Stroke Outboards:

        I bought this motor threethree years ago to chase spawning bass at a marina by my house as well as crappie up small creeks linked to out lake. It has been on a small 10 ft jon boat. Since purchase tye motor has had a disgusting "dead spot" in the carb on takeoff. If you don't barely twist the throttle to a spot it just revs above idle and let it catch up then it won't take off. It just falls on it's face and dies. Also I have had it three years but due to the drought our lake has bees down so much that I really havent usedd the motor at all. I would say it has a total runtime of about fifteen hours and this weekend I decided to take it to Tablerock lake with my girlfriends family. It ran ten minutes and started trying to die. The oil turned to milk and that is it. Do not know if it is a blown head gasket or a cracked block. Either way dont waste your money!!!

        (9 of 10 customers found this review helpful)

         
        1.0

        Stay away from the 3.5hp Outboard!

        By Kimberly

        from Portland, Oregon

        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:

        After owning a 6hp Mercury Marine Outboard and using it over that last five years I was confident in buying the 3.5hp for my tender. What a mistake. While my 6hp has been incredibly reliable and easy to work on the 3.5hp, right out of the box, has been finicky and downright unreliable. I have only put three hours on the motor and it has stranded me numerous times and has been incredibly difficult to start - not just for myself but for others whom have offered to help. I am going to attempt to return it and will report back on how it goes. I am VERY frustrated that I relied on the Mercury reputation rather than doing my due diligence and reading these reviews. While the engine is indeed compact and lightweight (the only reason for buying it instead of using my 6hp), as I told a friend, it's easier to get someone to help me to put a heavier motor on my transom than it is to get someone out into the middle of a channel to get a motor started.

        (7 of 7 customers found this review helpful)

         
        1.0

        Stay away from a 3.5 HP Mercury

        By Long-time boat owner

        from Santa Monica CA

        About Me Advanced

        Pros

          Cons

          • Unreliable

          Best Uses

            Comments about 2.5hp & 3.5hp 4 Stroke Outboards:

            I've owned outboard engines for decades, starting with a 3 HP Johnson in 1956. Our current dinghy has a 60 HP Yamaha, a wonderful engine. We also carry on board an inflatable dinghy and in August 2013 we bought a 3.5 HP Mercury for it from West Marine. On its very first use out of the box, the outboard was missing a part in the carburetor, had water in the carburetor, quit running and couldn't be restarted. We rowed a mile back to the main boat. The authorized repair dealer tested the fuel I'd put in the tank and the water wasn't in my fuel, it came from somewhere else. Nevertheless I was required to pay $95 to repair it because Mercury doesn't warranty carburetors and fuel problems. The engine still stalled repeatedly and was difficult to start, especially after it was warmed up. I paid another $95 to have it serviced again. I then learned the engine has a new fuel system and other owners are having the same problems as I did. The engine had only about 5 hours on it and I'd had enough of it and I was disgusted at Mercury's failure to stand behind its products. A week ago I went to a Honda dealer and gave them $500 plus my engine for a 2.3 HP Honda, a wonderful engine. Between the $190 in repair bills and $500 for the Honda, Mercury's engine cost me $690. Although West Marine wasn't able to do anything with Mercury, I remain a staunch supporter of West Marine. But please stay away from the 3.5 HP Mercury.

            Service and delivery comments:

            West Marine's delivery of the engine was excellent.

            (6 of 7 customers found this review helpful)

             
            1.0

            Bad Motor, Good Dealer

            By Steve

            from Rochester, NY

            About Me Advanced

            Pros

            • Compact Design

            Cons

            • Unreliable

            Best Uses

            • Boat anchor

            Comments about 2.5hp & 3.5hp 4 Stroke Outboards:

            I finally returned the motor (and I never return anything) because it was totally unreliable and left us stranded twice, the last time two miles from home. The manager of the local West Marine store was totally understanding and helpful. I exchanged (and paid additional) for a 6hp Mercury they had in stock. That motor is quite a bit heavier, but starts quickly, runs smoothly and promises to be a good choice. I put two hours on it the day I got it (observing break-in restrictions) because I was so gun shy about the one I returned. I miss the light weight, but reliability trumps that every time. Last night we took the dinghy (with new motor) to dinner and came back in pitch black for a 20-minute trip. It purred right along. Happy camper (boater) :) Trustworthy dealer.
            (The recommendation --one star---is for the old motor because that's the page I'm on. The new one seems excellent)

            (3 of 3 customers found this review helpful)

             
            1.0

            An Awful Motor

            By Steve

            from Rochester NY

            About Me Advanced

            Pros

            • Compact Design
            • Easy Storage
            • Light weight
            • No Mixing Oil

            Cons

            • Had To Be Towed 2 Miles
            • Just Bad
            • This Happens Repeatedly
            • Totally Unreliable
            • Will Just Stop Runningf

            Best Uses

            • Boat anchor
            • Small Rib

            Comments about 2.5hp & 3.5hp 4 Stroke Outboards:

            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

            (4 of 4 customers found this review helpful)

             
            2.0

            Disappointing So Far

            By Steve

            from Rochester NY

            About Me Advanced

            Pros

            • Compact Design
            • Easy Storage

            Cons

            • Unreliable

            Best Uses

              Comments about 2.5hp & 3.5hp 4 Stroke Outboards:

              I have only 4 hours on a new 3.5hp motor but I am concerned that the motor cuts out too easily after starting and then becomes tough to restart. Less of an issue when warm. This is weird because it is the exact same motor as Nissan and Tohatsu. Tohatsu makes all of them. You don't hear the same complaints about the others. I am hoping it will improve as it breaks in. I am using 10% ethanol gas but will switch to straight gas when the gallon I have is used. I do like that it is a 4 stroke and quite light in weight

              (5 of 6 customers found this review helpful)

               
              1.0

              Great Science Project, Lousy Motor

              By Scott

              from Connecticut

              About Me Advanced

              Pros

                Cons

                • Stalls And Won't Restart

                Best Uses

                  Comments about 2.5hp & 3.5hp 4 Stroke Outboards:

                  Bought a Mercury 3.5 from West Marine and it has been an enormous problem. Stranded often, almost from the start. Engine stalls after 10-20 minutes of use and will not restart for an extended period. Yesterday, with a Zodiac full of wife, 2 kids and Golden Retriever, I had the pleasure of a 30 minute row before a friendly neighbor came by and towed us back to our dock. After a series of fantastic Yamahas and Hondas there is precisely zero possibility I would ever own another Mercury. My 7 year old son feels similarly and hopefully will be a buyer of non-Mercury outboards for many decades to come.

                  (8 of 8 customers found this review helpful)

                   
                  1.0

                  DO NOT PURCHASE!!

                  By Irate Sailor

                  from Richmond, British Columbia

                  About Me Casual/ Recreational

                  Pros

                    Cons

                    • Unreliable

                    Best Uses

                      Comments about 2.5hp & 3.5hp 4 Stroke Outboards:

                      This motor is only useful as a paper weight. As an outboard to use to power or dingy to shuttle from shore to our sailboat and back at various anchorages, this motor has proven to be utterly unreliable, won't start, or once started, it stops for no reason we can discern. We have ended up rowing our rigid inflatable far more frequently than we have powered it with this motor. DO NOT BUY IT.

                      (4 of 5 customers found this review helpful)

                       
                      1.0

                      BUYER BEWARE!

                      By Ripper

                      from Calgary, Alberta

                      About Me Professional

                      Pros

                        Cons

                        • Jets In Carb Need Sizing
                        • Starts But Doesn't Run
                        • Unreliable

                        Best Uses

                          Comments about 2.5hp & 3.5hp 4 Stroke Outboards:

                          The jets in the carb are sized too small hence the fuel intake isn't enough to keep motor running. Don't buy this product unless you want to spend less time fishing than on motor repair.

                          (7 of 8 customers found this review helpful)

                           
                          1.0

                          Save for a larger engine

                          By SlapFish

                          from New Orleans, LA

                          About Me Casual/ Recreational

                          Pros

                          • Easy To Use

                          Cons

                          • Unreliable

                          Best Uses

                          • Canoeing

                          Comments about 2.5hp & 3.5hp 4 Stroke Outboards:

                          Put this engine on the back of my 12' jon boat. Not enough power to push the boat adequately. Pice is decent, but should've save a few hundred more for more of an upgrade.

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