IMP Boats Information

Discussion in 'Powerboats' started by JKE, Jan 17, 2005.

  1. rrumba
    Joined: Apr 2007
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    Location: georgia

    rrumba Junior Member

    Thanks Cougarman, I found out that the Tu-15S engine ID is a Buick 300 CID200 hp engine, a buick of all engines, go figure. Now I am trying to find the casting number information because the repair manual does not cover it. the website i found it on was

    http://hhscott.com/evinrude/stringer_models_72.htm

    No luck on the sterndrive yet, still looking.
     
  2. rrumba
    Joined: Apr 2007
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    Location: georgia

    rrumba Junior Member

    it is actually
     
  3. cougarman
    Joined: Apr 2007
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    Location: Payson, Arizona

    cougarman Junior Member

    rrumba, I looked at that web site and thats a pretty good site for info pretty easy to figure out, good job thank you, I hope you find some numbers on your outdrive, try looking down next to the lower fins for numbers stamped in casting Ive seen them stamped there before. Also look on the trim mount ive seen them there good luck. scott
     
  4. ENCHANTER
    Joined: Apr 2007
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    Location: FLORIDA

    ENCHANTER New Member

    Adding Horsepower To 350 Io

    Hello,
    What would be the best and most economical way to add 40 HP to a 260 HP Merc. 350 ? All input would be greatly appreciated ! Thanks.
     
  5. cougarman
    Joined: Apr 2007
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    Location: Payson, Arizona

    cougarman Junior Member

    Hello Enchanter,
    Thats a good question? There are a few things you can do but we need alittle more info on and about your,= boat?=motor?=outdrive?=prop? This would help all of us to try to figure out whats the best way to go, and whats most economical, I have found that this site has alot of knowledgable people here and alot of good information, and the people are great, so Im sure we all can help you figure this out. I will watch for your info, Thanks Scott
     
  6. ENCHANTER
    Joined: Apr 2007
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    Location: FLORIDA

    ENCHANTER New Member

    Thanks Scott,
    The boat is a restored 1987 21' Checkmate. The motor is a stock 87 merc 350CI 260HP 4 barrel carb I/O. The outdrive is an Alpha One with brand new lower end and gears. I'm currently spinning a Merc Mirage 23P prop and running 68MPH on GPS. I want to max the HP out to 300 for the Alpha outdrive recommended limit and get a few more MPH top end if possible. Any and all suggestions welcome !!
     
  7. cougarman
    Joined: Apr 2007
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    Location: Payson, Arizona

    cougarman Junior Member

    Enchanter,
    Sorry I havent got back to you sooner, Been thinking about you and rrumba lately and trying to gather info. About yours, Have you considered putting a larger cam and lifters in your engine, and I dont know what carb you have but there's another thing to consider and a intake manifold.
    Another thing is the gears and prop, Do you have a 13 1/4 x 23pitch prop? And have you tryed a 25 pitch prop? Have you talked with a local dealer about changing the gear ratio, Something to look into? Well just a couple of thoughts I hope this helps alittle. Scott
     
  8. cougarman
    Joined: Apr 2007
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    Location: Payson, Arizona

    cougarman Junior Member

    HAY RRUMBA
    Did your numbers disappear? And now you? Whats up
     
  9. rrumba
    Joined: Apr 2007
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    Location: georgia

    rrumba Junior Member

    i cannot find any number on the upper or lower unit or anywhere. Very frustrating. not sure if there is even one on there. i have another question though. I am replacing the transom seal, what would be the best thing to use as a sealer under the gasket between the transom and gasket?

    i think i will take some pics and see if anyone else might be able to see what my eyes are unable to.

    oh, another question, i just bought a prop for her, 14x16, is this the right size? does anyone know? it is a pin type not a spline.
     
  10. rrumba
    Joined: Apr 2007
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    Location: georgia

    rrumba Junior Member

    forgot..........

    No did not disappear, got stuck to the sterndrive trying to find numbers....lol

    roger
     
  11. cougarman
    Joined: Apr 2007
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    Location: Payson, Arizona

    cougarman Junior Member

    Sorry I havent responded sooner,
    Ive been out working on boats,,,,,,,, On your question about sealer? I use some silacone thats made by 3M and its waterproof and its paintable, its been working pretty good as far as I know, and on your spline, have you removed your prop yet? another clue does your prop have a # stamped on it?not just pitch and dia, but a part number? this may help us determine out drive, or at least narrow it down. well good luck, Im trying to get my boat in the water this sunday for the first time, I cant wait this could be interesting,,,,,,,, have fun Scott
     
  12. cougarman
    Joined: Apr 2007
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    Location: Payson, Arizona

    cougarman Junior Member

    Hay Enchanter,
    Any luck with adding 40 HP? I hope some suggestions were helpfull?
    well good luck Scott
     
  13. rrumba
    Joined: Apr 2007
    Posts: 9
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    Location: georgia

    rrumba Junior Member

    the guy i bought the boat from did not put the pin back in before he put it in the lake, then he started it and off the prop went. no idea what prop. from info that i have found on the web, most kinda point to a 14x16, so i hope that works. It is a pin drive. no spline.

    any 3m waterproof/paintable silicone? I found one at walmart that is for marine use, but you have to use it within 48 hours because it continues to set even with the cap on. Basically from what i am gathering you just want to put something in to help seal up behind it for imperfections, like permatex 2 does for engines?

    Thanks for all the help folks. Trying to put the boat in the water next weekend for the first time in about 5 years, from what the previous owner
    stated.
     
  14. Bill55AZ
    Joined: Aug 2006
    Posts: 24
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    Location: Peoria, AZ

    Bill55AZ Junior Member

    What I have learned so far, would appreciate you experts confirming it.
    Intermediate housing shafts pre 72 uses 2 roller bearings , one wider than the other. 1972 uses a tapered roller bearing with the race pressed? in to the housing. 73 and newer use a different shaft with threads on the end for a nut that keeps the ball gear on, don't know about the bearings.
    And the good part, it seems that all intermediate housings, at least through 77,are interchangeable as a complete unit with shaft, ball gear, bearings, etc.
    So it seems that you can take a unit from a 73-77 and upgrade your earlier units, assuming of course the motors are the same, as different brands of motors take a different shaft. One thing I am still fuzzy on, when did they change the spline count, if at all? I hear that around 77 or 78 they changed the spline count meaning you have to get the correct coupler from the flywheel as well. Again, all this is assuming you are not changing from chevy to ford, or vice versa. I know for a fact that the Ford shaft and coupler are not the same.
     

  15. Jeffbo
    Joined: May 2007
    Posts: 7
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    Location: Grandville, Michigan

    Jeffbo Junior Member

    1974 Inca

    Hi All,
    Happy to be on board.

    I am (but not my wife) a proud new owner of a 1974 IMP Inca. This boat needs a lot of work. I have a few questions about it. Where can I get a breakdown on the motor and outdrive? I was trying on the Volvo-Penta website site but it couldn't find anything on the setup I have. The boat has a 280 outdrive with a 350 ci Chris-Craft marine engine with aluminum valve covers on it. The guy I bought from claimed that it would run about 55 mph, I figured he stretching it a little, but when I saw the Corvette emblem on the Chris-Craft tag ( the circle with the two crossed flags) i figured it that it could be possible.

    Any information on the boat would be helpful, owners manual, history.

    Thank you
     
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