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  • New SBT engine running slow

    Question...I just installed a new SBT premium engine in my 900 zxi. It ran ok for a few tanks and now has lost power. I installed a block off kit when I installed the engine and have been premixing 50:1. The first day I installed the engine it struggled to get 55MPH. Today it is getting only about 45 MPH. I did a compression check and the first cylinder is only registering 40, the 2nd 120, and the third a full 130. Before I panic is there something I could be doing wrong in my checks? I know I have a 2 year warranty but it sucks to think I have to change out another motor.

  • #2
    Re: New SBT engine running slow

    The engine has obviously been damaged already. What caused the original engine to fail and what repairs were made? Please call in to Warranty for a replacement. 877 330 0231
    SBT Tech Support is here to help with your problems.
    We try to answer each question quickly and accurately.
    Please do not use Private Messaging for Tech Support, use the forums.

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    • #3
      Re: New SBT engine running slow

      The oil injection failed. That is why I put the block off kit on and ran 50:1 instead of my local repair shops recommended 3oz to a gallon. I ran 5oz to a gallon because I would rather fowl some plugs every now and then instead of changing out another engine.

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      • #4
        Re: New SBT engine running slow

        We'll know when the engine gets back, but I suspect you have at least one other issue.
        SBT Tech Support is here to help with your problems.
        We try to answer each question quickly and accurately.
        Please do not use Private Messaging for Tech Support, use the forums.

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        • #5
          Re: New SBT engine running slow

          I meant to mention I am only using Kawa Chem oil and no other brand even though Kawa Chem costs me more. I have done everything in my power to keep from being disappointed another summer. I don't try to run cheap and take chances to save a few $. I was disappointed I lost the original speed when I changed the last engine out. As I stated earlier, it struggled to reach 55MPH on the first tank with SBT break in oil in the tank. I hoped it was due to running the tank so rich. This ski could peg out at 60MPH easy with the previous engine after I rebuilt the carbs using SBT parts.

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          • #6
            Re: New SBT engine running slow

            First of all, you weren't doing 60. Only use the tach to gauge engine performance, not the speedo readout. Your ski topeed out around 52 actual MPH. Speedo's are called dream-o-meters for a reason.

            Second of all, you have a drop in compression which indicates the damage. It is most likely not oil related at all. How do you know you had an oil failure, exactly?

            Where do you have your carb adjustment needles set to? Have you ever done plug readings to verify mixture?
            SBT Tech Support is here to help with your problems.
            We try to answer each question quickly and accurately.
            Please do not use Private Messaging for Tech Support, use the forums.

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            • #7
              Re: New SBT engine running slow

              Maybe I don't know enough to swear it was oil injection failure but the last engine locked down and the block was smoking when I pulled the seat off. The top of the pistons were dry and the plugs were too. You guys should still have the core engine I sent in in late February. I am very new to engine change outs and I paid someone to do the engine that had to go in after I bought the ski with the third piston melted on the exhaust side. I do not know enough to know how to check the plug readings. How is that done? I can send digital pics of anything that might help solve why this happened this time. I know not to open the block up as this would void my warranty. If you have time to help figure out this failure let me know what you would like to see. Thank you for replying.

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              • #8
                Re: New SBT engine running slow

                Post all the pics you have.

                Melted piston means detonation.

                Smoking engine means overheat.

                No we don't still have the core it was immediately torn down an used when it arrived. We also do not inspect any cores.
                SBT Tech Support is here to help with your problems.
                We try to answer each question quickly and accurately.
                Please do not use Private Messaging for Tech Support, use the forums.

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                • #9
                  Re: New SBT engine running slow

                  Read through all the tech articles, there is a ton of info including plug readings and failure diagnosys. http://www.sbtontheweb.com/forum/forumdisplay.php?f=30
                  SBT Tech Support is here to help with your problems.
                  We try to answer each question quickly and accurately.
                  Please do not use Private Messaging for Tech Support, use the forums.

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                  • #10
                    Re: New SBT engine running slow

                    Will do...just for clarification the engine currently in the ski is a different one from the one that had a melted 3rd piston and a different one from the one that over heated and locked completely down. Just in case you are interested I have attached some pics of my initial tests after getting home from the lake yesterday. All plugs look identical out of the ski ...so I only included one plug shot.
                    Attached Files

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                    • #11
                      Re: New SBT engine running slow

                      The only pics that will help would be of the engines that failed, internally.

                      If you don't have any, you'll just need to wait for our warranty diagnosis after your block gets back here.
                      SBT Tech Support is here to help with your problems.
                      We try to answer each question quickly and accurately.
                      Please do not use Private Messaging for Tech Support, use the forums.

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                      • #12
                        Re: New SBT engine running slow

                        Called in today. Shiping out Wednesday. Any idea on how long turn around usually is?

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                        • #13
                          Re: New SBT engine running slow

                          2 days shipping to SC.
                          SBT Tech Support is here to help with your problems.
                          We try to answer each question quickly and accurately.
                          Please do not use Private Messaging for Tech Support, use the forums.

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                          • #14
                            Re: New SBT engine running slow

                            Before shipping I saw through the exhaust ports that the third piston was melted on the exhaust side for sure. Since I am not experienced enough to know how to recheck the carbs, I have handed them over to Superior Jetski here to have them go through them. I have also given them the stator and I have tested out the coils. Is there anything else I should look at while you guys check the engine out? The engine should arrive at SBT in the next day or so. Rg266

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                            • #15
                              Re: New SBT engine running slow

                              I would go through everything while the engine is out - no better time!
                              SBT Tech Support is here to help with your problems.
                              We try to answer each question quickly and accurately.
                              Please do not use Private Messaging for Tech Support, use the forums.

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