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Slow loss of power

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  • Slow loss of power

    Hello everyone, first and foremost thanks for anyone that has input on this frustrating issue.
    Ok, so I have a 2002 Saltwater series OX66 250 HP 2 stroke which has been running like a champ for the last couple of years.
    The last three times I've taken her out its had this issue. From the marina, I get up on plane without a problem however when I start to run regardless of the RPM (normally 4500-4700) is starts to slowly drop 1000 RPM at a time. If I give it more gas there is no effect whatsoever, it continues to drop. I would then have to reduce power then gun it and it speeds up again. It does this for the first 5 to 10 minutes. If I come off of plane and shut down the engine, once I start it up it runs completely fine the rest of the day. This has been the case all three times and I don't really know what could be causing it. I would assume its some kind of fuel restriction issue but not sure where to start. Thanks again for any and all help.

  • #2
    Can Anyone help???


    • #3
      Did you check your under cowl fuel filter for debis / water?

      If carberated(sp?), pull the drain plugs on the float bowls and catch what comes out, again looking for debris/ water. I use a tuna fish can which fits in most places..

      BTW, how old is the fuel, ethonol or not, any fuel stabilizer?

      A product that can only help is Yamaha's "Ringfree" which works very well at cleaning the fuel system and top end of the engine. Its not cheap but is very strong mixed @ 1 oz / 10 gallons. You won't hurt anything running it stronger than that.

      I run RingFree and K100 (cleaner/stabilizer/water eliminator) only, very happy with the results...
      1997 Angler 204 CC, 2006 F150 TXR