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90hp 2stroke seized

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  • 90hp 2stroke seized

    Been having lots of issues lately, if I let the engine sit for a week, it will begin to seize. I pull the plugs a slowly force the flywheel. Reinstall plugs and start her up. Lately lots of oil coming out of carbs into intake. Did my oil injection fail and engine not getting oil?

  • #2
    Maybe you have broken reed valves when there is much oil in the intake. If you have then your motor is probably going to size bc of steel reeds in crankcase and cylinder.

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    • #3
      Doesn't make a lot of sense when you say there is lots of oil, but then suspect lack of oil as the problem.

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      • #4
        Yeah I just reread it. When oil injection fails doesn't it overfill the engine? How do you check Reed valves?

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        • #5
          are the cylinders getting water or oil into them causing the motor to hydrolock?
          Do you see anything on the plugs

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          • #6
            Originally posted by tony351c View Post
            Yeah I just reread it. When oil injection fails doesn't it overfill the engine? How do you check Reed valves?
            Remove the carbs and look at the reeds with a flash light, use a screw driver to gently push them open so you can see the edges. You will notice if there are pieces missing or if they are cracked.
            Last edited by holmen78; 01-22-2019, 10:58 AM.

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            • #7
              Thanks guys, will the carbs and have look.

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              • #8
                I will pull the carbs out and have a look

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                • #9
                  Clean the carbs wyle you have them off. If you can get a bore scope check the cyld's out if not pull the head and look.

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                  • #10
                    I would suspect exhaust jacket....may have pin hole and letting water into cylinder. Usually one plug will have moisture/rust.

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                    • #11
                      that is why I asked if he looked at the plugs, but got ignored.
                      something is stopping the motor from turning, if it is not in the motor then maybe it would be the lower unit.
                      but someone will have to be checking things out.
                      look at the plugs and cylinder walls.
                      drop the lower unit to see if that helps

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                      • #12
                        Didn't get a chance to look at it today, the plugs were dry, all three were different. I'll take pics, but when I work the flywheel loose she will restart with no issues. I recently did an impeller and oil change with no water in the lower case. Carbs were rebuilt at same timeframe as well. On a recent trip she did smoke a lot more than usual but restarted everytime.

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                        • #13
                          I really appreciate all the advice, thanks again.

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                          • #14
                            Just to clarify "the seizing".

                            Once started and running turn off and let cool down. Once cool (that day, maybe an hour later), pull the plugs and see how easy the engine spins over COMPARED to the initial pressure to hand spin the engine.

                            **Just trying to rule out a bad battery, bad electrical connection, failing starter. Starting cold, generally takes more electrical power (would show up more so with anything failing/borderline)

                            Might want to run pre-mix for now till you find the issue..


                            I would think, if a reed was broke, you'd be getting mucho blow back thru one of the carbs (No seal when the piston goes downwards in its stroke)

                            Also, the extra oil, is any of that coming out of the combustion chamber when you pull the plugs? (hydraulic lock from leaking oil/ fuel??)
                            Last edited by TownsendsFJR1300; 01-23-2019, 08:26 AM.
                            Scott
                            1997 Angler 204, Center Console powered by a 2006 Yamaha F150TXR

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                            • #15
                              check your bleed lines going to the upper and lower crankshaft bearings, that is what lubes them.

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