2003 Polaris MSX 140 Personal Watercraft Service Manual, Page 81Get this manual
EngineCooling W120HO- DFI Crankshaft Indexing Polaris DIt engines have fuel injector mounted in place of the standard spark plug holeThe spark plugs on DIt engines are mounted on the side of the cylinder headsBecause of this arrangement, the use of bumper tool, PN 2872604, is required to establish the degree wheel timing marksCAUTION: Disconnect battery ground cable and all spark plug high tension leads; ground high tension leads to engineDisconnect lanyard from engine stop switch before proceeding with the following stepsIll1 1Securely fasten degree wheel on the flywheel or output couplerdriveshaftUse large degree wheel for more accuracy, and make sure it is mounted concentrically with the crankshaft center lineCut slot in paper or cardboard degree wheel and slide it over the driveshaft if engine and pump shaft is installed in craftAgain, be sure to secure the degree wheel2Sharpen coat hanger or section of welding rod and anchor it to convenient spotPoint the sharpened end at the outer perimeter of the flywheel or drive coupler mounted degree wheel3Install bumper tool PN 2872604 into the magneto end cylinder spark plug hole (front) (#1)(The ignition timing is referenced by the magneto end 4Rotate the engine to bring the piston to the top of the cylinder, making contact with the bumper toolScribe mark on the degree wheel(See Ill1) 5Rotate the engine in the opposite direction until similar contact is made with the bumper toolScribe another mark on the flywheel(See Ill2) 6Once both scribes are in place, remove bumper tool and record the measurement between both scribes and divide it in halfMake scribe in the middleThis is Top Dead Center7Bend the pointer or move the degree wheel until the pointer aligns with the 120 mark on the degree wheel8Verify the mark be performing steps and againRotate until resistance is felt Piston Degree Wheel Bumper Tool PN 2872604 Scribe Mark