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  1. #1

    Default 1961 - 1974 Cresent Marin 4 or Monark 4

    Hi all,

    I recently aquired an unknown outboard, it is a mixture of orange and white, The only markings on the cover is a number 4. I managed to find a half legible serial number on the side and a part number off the leg. Having researched it a little bit I have deduced that I have a Cresent Marin 4 or Monark 4.
    Apparently this is the same engine as a volvo archimedes penta 4hp. It has good compression, nice clean gearing and have cleaned carb and fuel tank. Unfortunatly there is no spark.
    I have removed wiring from cut off switch, also the wiring went to a panel at the front with 2 small holes in it side by side. I have removed all of this wiring and connected straight from primary coil (on stator) to points, This is what the wiring looked like it was doing in a round about way. Would like to get engine going, if need to stop can just cut off fuel, block air or worst case remove carb (easy to do).
    I have checked primary coil for resistance (ok) secondary coil from spark plug lead to other output terminal reads 3.6kohm and I believe it is supposed to be 6ohm.
    The secondary coil is encased in plastic and I have tried to remove this with no joy.

    Where can I get parts from? (I'll post a picture tomorrow of stator and see if anyone recognises)
    The secondary winding has a part number of Bosch 11Z 3, I was hoping to renew this but can't find anything similar

    Which sparkplug do i need for this o/b?

    Thanks

    Gav

  2. #2

    Default Re: 1961 - 1974 Cresent Marin 4 or Monark 4

    I have managed to find a picture of the stator (my coil is enclosed with black casing) He also states that the resistance should be 4kohm?
    https://picasaweb.google.com/arnexlu...93692315779890
    Apparently it's a NV-Marin Stefa ignition. Made in Sweden. On blue coil: STEFA SUPERMETIC Cat. Nr. 29102.
    However i'm not having much luck finding a new one

  3. #3

    Default Re: 1961 - 1974 Cresent Marin 4 or Monark 4

    Another thought isthat whole ignition might be ok. In this case maybe i've buggered it by removing cut-off switch. Would anyone happen to know correct wiring config or what the 2 round holes are for in the following picture?
    https://picasaweb.google.com/arnexlu...13892542390770

  4. #4
    mrcrabs
    Guest

    Default Re: 1961 - 1974 Cresent Marin 4 or Monark 4

    I know what the holes are for, its for the light's thats why you have that big charge coil...we can't have people banging around at night in the fjord with no lights.

    of course you have checked plug wire boot? I don't know exactly unless I was hands on with it but sounds like it should fire ...nothing extra ordenary there, however I would be looking to put back the charge coils wiring

  5. #5

    Default Re: 1961 - 1974 Cresent Marin 4 or Monark 4

    Thank you very much for your reply. I shall rewire, before I do does anyone know the correct wiring? This is my first outboard and I want to wire it back up correctly. There is a push button on the front of the handle/steering boom thing.
    This is how I think it was wired and it doesn't make much sense to me.
    Earth - Light Coil - Lights Pos - (Lights Neg - Switch - Points)
    Points - Capacitor - Main Coil - Spark Plug Lead - Spark Plug - Earth.
    The bit in brackets is the bit i'm unsure about.
    Also how does the Spark system work? Does the spark fire when the points move apart?

  6. #6

    Default Re: 1961 - 1974 Cresent Marin 4 or Monark 4

    Ok. Quick update as i managed to get the old girl started on friday. Even though I had previously filed down the points I unsoldered everything I could and had o/c when points were closed. Filed them again with success.
    Using an old sparkplug I got a couple of puts after 20 minutes of trying to start the engine up. Swapped the spark plug for one of those see through jobs (used to adjust mixture). Struck up and sounding sweet. Good luck to anyone else with an old engine. Feel free to send me a message if anyone has any problems with these crescent O/B's and i'll try my best to pass on all the info i've learned over the past 3 - 4 months.

  7. #7

    Default Re: 1961 - 1974 Cresent Marin 4 or Monark 4

    I have rebuilt a 3hp nv marine crescent, you got any manuals or any literature for your 4hp? I've also got spark problems too, however I think the 60 year old condensor is tired

  8. #8

    Default Re: 1961 - 1974 Cresent Marin 4 or Monark 4

    Hi Archie, I initially thought that my condensor was fried. Couldn't find any manuals for these but if you carry out some resistance checks of the condensor with it disconnected and post your results. I also found a poor connection from ht lead to spark plug "clamp".
    I've just bought a brand new HT lead
    Does anyone know if I can just splice the internal carbon of the new HT lead to the Metal cable of the old HT lead?

  9. #9
    Petty Officer 1st Class
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    Default Re: 1961 - 1974 Cresent Marin 4 or Monark 4

    Quote Originally Posted by gavincollison View Post
    Hi all,

    ...
    I have checked primary coil for resistance (ok) secondary coil from spark plug lead to other output terminal reads 3.6kohm and I believe it is supposed to be 6ohm.
    ...
    Hi Gavin,

    The 3.6KOhm for the secondary is about right, 60 Ohms would be way low!

    Good luck, Peter

  10. #10
    Vice Admiral
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    Default Re: 1961 - 1974 Cresent Marin 4 or Monark 4

    Quote Originally Posted by gavincollison View Post
    I've just bought a brand new HT lead
    Does anyone know if I can just splice the internal carbon of the new HT lead to the Metal cable of the old HT lead?
    You must use the metal spark plug wire, not the automotive type carbon fiber stuff.
    Please no PMs. My mailbox is full anyway......

  11. #11

    Default Re: 1961 - 1974 Cresent Marin 4 or Monark 4

    Hi Gavin

    ...or anyone else

    I have bought a Crescent 4hp, also with spark problems. It sound like the same model or close to, as far as I can tell from your description.

    hej 357.jpg

    I have a problem taking the "starter housing" off. (I'm not sure its the right word for it)

    I have removed the top nut and the two bolts on each side.

    hej 352.jpg hej 353.jpg

    Do I need a special tool or have I missed something here?

    Thanks

    Soeren /Denmark
    Attached Images Attached Images

  12. #12
    Petty Officer 1st Class
    Join Date
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    286

    Default Re: 1961 - 1974 Cresent Marin 4 or Monark 4

    That is thee flywheel you want to take off. You take the top nut from the crankshaft off and then use a puller. The puller is a special tool for removing the flywheel.
    Here is a picture of the puller: https://plus.google.com/photos/11837...11274193974716

    Good luck, Peter
    Last edited by orbanp; August 13th, 2013 at 08:54 AM.

  13. #13

    Default Re: 1961 - 1974 Cresent Marin 4 or Monark 4

    Yep get a puller, they worth having for other stuff too. I tried hitting the bolt with a hammer to dislodge it but buggered it

  14. #14

    Default Re: 1961 - 1974 Cresent Marin 4 or Monark 4

    Many thanks, both of you.

    That was really helpful... I've been pulling and banging that thing for ages, without a result...

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