User manual PIAGGIO MSS X9 EVOLUTION 250

[. . . ] WORKSHOP MANUAL 618153 MSS X9 Evolution 250 WORKSHOP MANUAL MSS X9 Evolution 250 The descriptions and illustrations given in this publication are not binding. While the basic specifications as described and illustrated in this booklet remain unchanged, PIAGGIO-GILERA reserves the right, at any time and without being required to update this publication beforehand, to make any changes to components, parts or accessories, which it considers necessary to improve the product or which are required for manufacturing or construction reasons. Not all versions/models shown in this publication are available in all countries. The availability of single models should be checked at the official Piaggio sales network. [. . . ] REPLACE THE CRANKSHAFT IF THE DIAMETER OF THE ROD SMALL END EXCEEDS THE STANDARD DIAMETER OR IT SHOWS SIGNS OF WEAR OR OVERHEATING. Characteristic Rod small end check-up: Maximum diameter 15. 030 mm Rod small end check-up: Standard diameter 15 +0. 015+0. 025 mm ENG - 111 Engine MSS X9 Evolution 250 Inspecting the wrist pin - Measure the outside diameter of the gudgeon pin. - Calculate the coupling clearance between pin and connecting rod end. Characteristic Pin diameter: Standard clearance 0. 015 ÷ 0. 029 mm Pin diameter Standard diameter 14. 996 - 15. 000 mm Inspecting the piston - Measure the diameter of the wrist pin seat on the piston. - Measure the outside diameter of the piston, perpendicular to the gudgeon pin axis. - Take the measurement at 5 mm from the base in the position shown in the figure. - Measure the coupling clearance between the sealing rings and the grooves using suitable sensors, as shown in the diagram. - If the clearance is greater than that indicated in the table, replace the piston. N. B. MEASURE THE CLEARANCE BY INSERTING THE BLADE OF THE FEELER THICKNESS GAUGE FROM THE SECOND SEAL SIDE. FOR THIS REASON MEASUREMENT OF THE DIAMETER MUST BE CARRIED OUT ACCORDING TO THE AXIS OF THE PISTON. Characteristic Wrist pin seat on the piston: Standard diameter 15. 001 ÷ 15. 006 mm Diameter of the wrist pin seat on the piston: Standard clearance 0. 001 ÷ 0. 010 mm ENG - 112 MSS X9 Evolution 250 Engine piston diameter 71. 953 - 71. 981 mm Fitting clearance Top piston ring - standard coupling clearance 0. 015 - 0. 06 mm Top piston ring - maximum clearance allowed after use 0. 07 mm Middle piston ring - standard coupling clearance 0. 015 - 0. 06 mm Middle piston ring - maximum clearance allowed after use 0. 07 mm oil scraper ring - standard coupling clearance 0. 015 - 0. 06 mm oil scraper ring - maximum clearance allowed after use 0. 07 mm Inspecting the cylinder - Using a bore gauge, measure the internal diameter of the cylinder following the directions given in the figure and at three different heights. - Check that the plane of coupling with the head does not show wear or deformations. - The pistons and cylinders are classified with categories depending on the diameters. The coupling is carried out matched (A-A, B-B, C-C, D-D). Characteristic cylinder: standard diameter 71. 990 - 72. 018 mm (at 33 mm) Maximum allowable run-out: 0. 05 mm ENG - 113 Engine MSS X9 Evolution 250 Inspecting the piston rings Removing the piston - Install piston and wrist pin onto the connecting rod, aligning the piston arrow the arrow facing towards the exhaust. - Fit the wrist pin stop ring onto the appropriate tool - With opening in the position indicated on the tool S = left D= right - Place the wrist pin stop ring into position using a punch - Fit the wrist pin stop using the plug as shown in the figure N. B. CAUTION USING A HAMMER MIGHT DAMAGE THE STOPS' HOUSING. Specific tooling 020454Y Tool for fitting piston pin stops (200 250) ENG - 114 MSS X9 Evolution 250 Engine Choosing the gasket - Provisionally fit the piston into the cylinder, without any base gasket. - Assemble a dial gauge on the specific tool - Set the dial gauge to zero placing the tool on a contrasting surface. Keeping the zero position, assemble the tool on the cylinder and lock it with 2 supplied nuts as shown in the figure. - Rotate the crankshaft until TDC (the inverted point of the dial gauge rotation) - Position the dial gauge on the piston as shown in the figure and measure how much the piston protrudes. - Identify the thickness of the cylinder base gasket to be used for reassembly by the table below. Correctly identify the cylinder base gasket thickness to keep the correct compression ratio. - Remove the special tool and the cylinder. N. B. MEASUREMENT "A" TO BE TAKEN IS A VALUE OF PISTON RE-ENTRY, IT INDICATES BY HOW MUCH THE PLANE FORMED BY THE PISTON CROWN FALLS BELOW THE PLANE FORMED BY THE TOP OF THE CYLINDER. THE FURTHER THE PISTON FALLS INSIDE THE CYLINDER, THE LESS THE BASE GASKET IS TO BE APPLIED (TO RECOVER THE COMPRESSION RATIO) AND VICE VERSA. Specific tooling 020428Y Piston position check support ENGINE 250 SHIMMING Name shimming shimming shimming Measure A 3. 70 - 3. 60 3. 60 - 3. 40 3. 40 - 3. 30 Thickness 0. 4 ± 0. 05 0. 6 ± 0. 05 0. 8 ± 0. 05 ENG - 115 Engine MSS X9 Evolution 250 ENG - 116 MSS X9 Evolution 250 Engine Refitting the piston rings Fitting the sealing rings - Place the oil scraper spring on the piston. - Refit the oil scraper ring with the join of spring ends on the opposite side from the ring gap and the word 'TOP' towards the crown of the piston. The chamfered side of the oil scraper ring should always be facing the piston crown. [. . . ] - Unscrew the four fixing screws of the holding bracket indicated in the figure and remove it; - Unscrew the two fuel tank fixing screws, located on the upper part; - Slide off the tank downward after tilting it slightly. CHAS - 209 Chassis MSS X9 Evolution 250 N. B. this operation should be preferably be carried out with the tank empty. Rear central cover - Unscrew the 4 fixing screws; - Remove the rear centre cover. CHAS - 210 MSS X9 Evolution 250 Chassis Radiator fan - Prepare a container for the coolant. - Remove the delivery and reverse pipes of both the expansion tank and the radiator coolant; - Disconnect the connector from the thermostat pipe; - Unscrew the fixing screws and release the radiator and the electrical fan. Expansion tank - Unscrew the fixing screws from the expansion tank support and remove the support; - Slide off the expansion tank downwards with the relative gasket after removing momentarily the cap; - Prepare a container for the coolant. - Close the cap again and remove the coolant delivery and reverse pipes. Top-case - Unscrew the fixing screws from the electrical connection indicated in the figure; - Remove the expansion tank as described before; - Unscrew the screw inside the case and remove it together with the saddle latch transmission. CHAS - 211 Chassis MSS X9 Evolution 250 Handles and top side fairings - Remove the rubber plugs covering the fixing screws; - Unscrew the socket head screws and remove them; - Remove the passenger handles. [. . . ]