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1978 40hp twin 2stroke manual wanted

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  • 1978 40hp twin 2stroke manual wanted

    Hi folks I'm wondering if anyone can help, I'm looking for a workshop manual for Yamaha 40hp BR40 676S engine number. 25080
    Also any hints and tips about this engine
    I just bought a package of a 4mtr DSB zephyr SIB with the 40hp
    . It has been used in fresh water only and is in very good condition, the engine, I've started to service it I stripped the carbs and cleaned all the jets and air and fuel ways I've dropped the lower case oil, removed the prop and away top drop the lower case to replace the water pump. On inspection the wiring is all good and have checked the spare mag coil wire and resistance seems to be good, not sure what it's used for unless charging a battery via a rectifier.
    Any info would be great
    Many thanks

  • #2
    probably need to look around where you are for the service manual, that motor or any Yamaha motor were not shipped to or available to the USA until the early 80s. so will not find one around here


    • #3
      The first Yamaha 40 HP two stroke offered here in the USA was the 1984 40SN/40LN (different shaft length). They, however, are 6H4 prefix motors, not 676 prefix motors.

      I can't tell you where to find the specific service manual for your particular model. However, our 40SN/40LN use SM LIT-18616-00-11. If you cannot find a specific manual for your model you probably can get quite a bit of useful information from a USA 40SN model manual. If you want to buy one you can get it directly from Yamaha USA here


      or a bit cheaper from a Yamaha USA dealer here

      You can also view the 40SN parts catalog for free. Maybe look at the configuration of this model to determine to what extent it looks like your motor.
      1984 40SN Yamaha Outboard Parts

      Regarding the extra coil, many Yamaha manual start models come without a rectifier/regulator installed. An alternate R/R is sometimes available for connection to what Yamaha calls the "lighting" coil. The lighting coil leads are usually green in colour.
      Last edited by boscoe99; 01-09-2017, 03:57 PM.


      • #4
        Thanks very much guys your help much appreciated
        I will check and look over the info you have given me
        Many thanks again