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Johnson 9.9hp to 15hp????

Discussion in 'Boats and Motors' started by smallieguy, Feb 14, 2005.

  1. smallieguy

    smallieguy Smallmouth Please

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    1st off, sorry to the moderators is this is a repeat post.

    Does anyone know the exact way to convert a 2000 johnson
    9.9hp short shaft manual start to a 15hp?
    Looking for a little more got out of my own way if you know what
    I be sayin' :D
     
  2. All you have to do is put a 15 hp carb on it and do a bit of re-adjustment. Don't bother with the exhaust port as most of the punch comes from the carb.
     

  3. smallieguy

    smallieguy Smallmouth Please

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    Do you know where I can get a carb. besides Norton marine?
     
  4. A website by the name of www.smalloutboards.com has an excellent article on this very subject. Scroll down once you get on the site and read what they say.
     
  5. smallieguy

    smallieguy Smallmouth Please

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    Thank You :D i guess i'm callin norton.
     
  6. smallieguy

    smallieguy Smallmouth Please

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    Called Norton and Don said they could take care of me right away,so
    I got it there the same day and the price was great so it will done asap.
    And they are doing the exhaust ports ;) thanks Shortdrift.
    papaperch your post made up my mind, THANKS :D
     
  7. i got a 9.9 yamaha 4 stroke can u do the same and i have a 25 mariner can u make that the same way to.
     
  8. smallieguy

    smallieguy Smallmouth Please

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    Take a look at yamahas website and see if they use the same
    engine for 9.9 and 15 or 25 and?
    that will tell you if you can upgrade the hp.
     
  9. Some are upgradeable and some not. The manufacturer will never tell you but the dealer will.
     
  10. smallieguy

    smallieguy Smallmouth Please

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  11. LiquidTension

    LiquidTension mouse potato

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    wouldnt be planning on using that on some 10 hp lakes would we?

    soooooo can i take my 40 hp to some 10 hp lakes and just use 1/4 throttle :rolleyes: ???????? i swear not to make a big wake.... oh wait.... the boats not gonna get on plane........ its gonna make a wake just as big as a 15 or 25 hp thats not on plane
    hummmm maybe i can get a 50hp carb to throw on there.... that'll fool 'em

    just sayin'........ silly restrictions.... what was i thinkin' ...... pffftttttt

    :not ripping smallieguy: just sayin' ;)
     
  12. smallieguy

    smallieguy Smallmouth Please

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    A converted 9.9 to 15 and use it on a 9.9 lake? :eek:
    Who me? :rolleyes:
    Well I'd never do that. ;)
    Like I'd be the only one in Ohio to ever try that.

    No offense taken, I just like to know the answers to questions before
    they are asked...ie: can you make a 9.9 a 15 or can you make a 40
    a 50.
    well yes if the engine specs are the same EXCEPT for carberation
    and exhaust and props.
    think of a 1970 chevy 350 with a 2barrel carb and then switch it
    to a 4barrel.
    horsepower will increase, period.
     
  13. It has happened before. I know of a guy running a merc 25 hp with 9.9 stickers on it. he has never been questioned about it.
     
  14. smallieguy

    smallieguy Smallmouth Please

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    Thanks to all for the advise but in the end I desided not to
    have the work done.
    It just wouldn't be worth the $
     
  15. smallieguy:
    I am going to do the same thing with my JOHNNY 9.9 .I have a SEA NYMPH 17.5 and it's the slowest thing on the lake besides POTOON boats.I have a wooden deck that gives the boat a lot of weight.I'M going to take mine to a place across the river in Wheeling WVA.Those people are very good.Some of the boats on PIEDMONT are really fast for a 9.9 ! :rolleyes:
     
  16. smallieguy

    smallieguy Smallmouth Please

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    Thats the truth about the pied.
    I had one of the fastest boats on the lake and then went and got a bigger boat. :eek:
    slowed me down from 22mph to 16mph on my gps and on good day.
     
  17. smallieguy:
    :eek: 22 to 16!! On a GOOD morning I might hit 10 mph...and in the wind try 6 for me. :( ...I have aimed the boat,put my head down ,and shut my eyes when nobody was on the lake because it takes so long......lol. :D
     
  18. It sounds like you may have to install a mast and sail on that "wooden ship".:D;)
     
  19. smallieguy

    smallieguy Smallmouth Please

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    Heck one day on milton with a 10-15mph tail wind my gps said
    24.7 mhp. And yeah it was scarey. :D
     
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