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  1. #1

    GP1200R engine assembly questions

    Hello all. I just finished building the engine for an 02 gp1200r due to a bad cylinder and piston (and whatever else I found). I was turning the engine over by hand without the plugs in to see if the rings were holding. I found that #2 and #3 have compression with my thumb over the spark plug hole, #1 does not. I used new rings in all three cylinders, but the pistons are used. When putting the rings on the first piston, the rings stayed shut after being compressed by hand. Do you guys think they will released once fired? Or will it even fire at all?

    Second, I jumped the starter just to make sure it still works before I drop the engine in. The gear that engages the flywheel did not retract after engaging. Will this release once the engine is under its own power? Thanks, guys.

  2. #2
    WATER WOODY's Avatar
    Join Date
    Aug 2005
    Minden, Nevada, United States
    You got problems if #1 is dead. You need to pressure test anytime you build one of these engines. Get yourself a compression guage and test compression. Get it tested and post back, i would not start it yet.

  3. #3
    Yeah, that's what I figured. I did pressure test it and all is well with that. I haven't done a compression check yet, but can tell the rings aren't seated. I think the rings are a bit tight in the piston themselves. Thanks. I'm just nearing frustation at this point. I've been close to the end so many times, but keep finding things wrong.

  4. #4
    All hail the Chief! fullboogie's Avatar
    Join Date
    Nov 2005
    If the rings in #1 did not expand out once you fit them to the piston, you have a slightly crushed ring land or a burr in there. Either way, time to get a new piston.

    Piston rings should not stick in the grooves.

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