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  1. #1

    Join Date
    Dec 2008
    Chicago Northwest Indiana

    Carb v. DI and RFI models

    1st post everyone. I've been reading all the info I can about Sea Doo injection systems but it seems there is little you can do to diagnose / repair these things without the help of a dealer. I am looking to get into a ski soon and have been looking at 3seaters (2stroke) with a 951 motor. Why is it that the horsepower ratings are different between the carb, DI, and RFI models? Not too sure of the drawbacks to the injection systems other than the inability to work on them but need to know what others think of the reliability of the earlier 2-stroke injection systems 1998-2003? Do the injectors clog up at all? Lastly which of these systems have proved most reliable / trouble free?

  2. #2
    Prohibido usuario
    Join Date
    Aug 2005
    Jerry's guest bedroom
    Least problematic 951 is a tie. They all are money pits. If you can afford it and want a Sea Doo get a 4 tec. Before I would spend $1500 on a 2 smoke I would save $1500 more for a 4 tec. If set on a cheap 2 smoke look at the yamahas. SD is getting out of the 2 stroke ski business (for now) and parts will become hard to obtain.

  3. #3
    A carb 951 motor will last you a very long time if taken care of. Common reason for failure is water getting into the motor. I would use and exhaust manifold from a 2001+ motor with the oring gasket. Make sure the carbs are clean and the fuel lines are not the grey ones, if they are, change them. My 2000xp, and 2002xp both have the original 951 carb motors in them. (that is in the process of changing)

  4. #4
    " Why is it that the horsepower ratings are different between the carb, DI, and RFI models? "

    All RFI engines are 782cc's and are rated @ about 110 h.p.

    Both Carb'd and and DI 947 engines are rated at 130 h.p.

    The extra sensors supporting both RFI (Rotax Fuel Injection~Port Injection) and DI (Direct Injection~into the Cylinder Head) makes these type of engines more expensive to fix if/when they fail since troubleshooting the fuel delivery system/sensors requires the dealer to hook up a diagnostic computer.

    2001 and newer Carb'd 947's and DI's both use better sealing around the Exhaust Flange (Viton O-Ring vs. previous years Paper Gasket).

    This is where most of the water leakage problems occur
    on UN-Modified 947 engines, either DI or Carb'd.

    Fuel Lines (Internal degradation) were never a problem on the DI's or RFI's since they always used a different type than the Carb'd 947's. If you go with a Carb'd 947 engine, be absolutely sure to replace those Gray Fuel Lines, douche out the Fuel Tank gunk and clean/rebuild the Carbs.

    Last edited by David_HX_RXP; 01-25-2009 at 12:14 PM. Reason: ~

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