NOTES: In addition to this workshop manuals texts and pictures transcribed from original Piaggio/Gilera manuals, there is included a section on the various known faults with which the Saturno is prone to suffer. Whilst these faults were obviously not included in the original official manuals, we believed they should be a part of any publication dealing with Saturno maintenance.
INDEX Section General information - Known faults Special tools Maintenance ENGINES Working procedures Engine removal/installation Generator - Timing belt - Gearbox selector Cylinder head - Valvetrain components Cylinder - Piston Clutch - Primary drive - Oil pump Crankcase - Gearbox - Crankshaft components FRAMES Working procedures Front Wheel...
GENERAL INFORMATION SUB INDEX Section - Page Known faults 1 - 1 Safety procedures 1 - 2 Maintenance procedures 1 - 2 Model Identification 1 - 2 Technical data 1 - 3 Torque wrench settings 1 - 4 Engine overhaul data 1 - 5 Cables and wire passage 1 - 6...
KNOWN FAULTS 1 - 1 Fan touches Radiator. Remove tank, look down back of radiator & check that fan shroud has about 3mm (1/8”) clearance. The fan mountings are slotted but if there is not enough adjustment, trim the front of the shroud.
MANTENANCE PROCEDURES 1 - 2 Always use original GILERA spare parts and recommended lubricants. The use of non-original parts or parts not conforming to Gilera specifications may result in damage to the motorcycle.
TECHNICAL DATA 1 - 3 DESCRIPTION 350cc - 500cc DIMENSIONS Overall length 2030 mm Overall width 730 mm Overall height 1170 mm Wheelbase 1410 mm Seat height 790 mm Foot pedal height 360 mm Dry weight 145 kg FRAME Triangulated tubular steel space frame Steering column angle 24.3 30’...
TECHNICAL DATA 1 - 3 350cc - 500cc ENGINE Single cylinder, 4 stroke, vertical cylinder Bore X stroke 80 X 69.4 - 92 X 74 Displacement 348.8 cc - 491.9 cc Compression ratio 9,5:1 - 9,8:1 Cylinder compression (use special tool 19.1.20524) New engine 9 ÷...
ENGINE OVERHAUL DATA 1 - 5 350cc - 500cc Piston/cylinder clearance 0.030 ÷ 0.042 mm Main bearings radial clearance 0.030 ÷ 0.059 mm Connecting rod bearings radial clearance 0.017 ÷ 0.060 mm Crankshaft axial clearance 0.05 ÷ 0.25 mm Big end axial clearance 0.15 ÷...
CABLES AND WIRE PASSAGE 1 - 6 Point out the passage of each cable and wire (figs. 5-6-7-8-9). 1 - 6...
SPECIAL TOOLS Sprocket locking wrench Camshaft oil ring installation punch 19.1.20086 19.1.20503 Puller for steering bearing lower race Camshaft pulley blocking tool 19.1.20109 19.1.20504 Flywheel puller Con-rod small end bushing 19.1.20501 installation punch 19.1.20505 Valve guide oil ring Con-rod small end bushing installation punch extraction punch 19.1.20502...
SPECIAL TOOLS Main journal bearing extraction ring Main journal bushing extraction punch (ignition side) 19.1.20507 19.1.20511 Main journal bearing installation punch Piston support (clutch side) 19.1.20508 19.1.20512 Main journal bearing installation punch Pad for crankshaft and (ignition side) flywheel puller 19.1.20509 19.1.20513 Main journal bearing extraction ring...
SPECIAL TOOLS Engine support Pin sliding punch 19.1.20526 19.1.20530 Engine support base Battery charge density meter 19.1.20527 19.1.20564 Complete roller cage extractor Chain slack tool 19.1.20528 19.1.20565 Reamer set for valve seats Punch 19.1.20529 19.1.20566...
SPECIAL TOOLS Clutch collets tool 19.1.20540 Exhaust manifold spring removal tool 19.1.20551 Complete tool kit 19.1.20563...
MAINTENANCE 3 - 3 ADJUSTMENTS Fuel level Turn over carburettor and let float rest on the needle valve’s damper spring without pressing. Check distance between bowl gasket seat and uppermost edge of the float with proper gauge. Float level = 24 ± 2 mm Adjustment is made by bending slightly the float tongue.
MAINTENANCE 3 - 4 CYLINDER COMPRESSION Warm up engine. Stop engine and remove spark plus (remove tank if necessary). Insert compression gauge (19.1.20524) in spark plug hole. Turn throttle fully open and turn engine over with the electric starter until the gauge measures the highest value.
MAINTENANCE 3 - 5 THROTTLE CONTROLS Check that the throttle grip turns freely from fully open to fully closed in all steering positions (fig. 12). Lubricate the throttle cable if found to be sticking. Verify that the throttle grip has 2 to 5mm play; replace if found defective. The end of the throttle cable goes in the hole in front of the throttle grip (fig.
MAINTENANCE 3 - 6 Chain replacement Remove pinion cover. Remove pinion bolt and remove pinion (fig. 17). Remove gearshift rod. Loosen the bolt on the lower part of the engine and lift it out towards the right (fig. 18). Remove spacer bushing. Remove chain guard cover.
MAINTENANCE 3 - 7 ENGINE OIL LEVEL CHECK Stand the motorcycle in a vertical position, on a flat surface. Start up the engine and let it run at idle speed for about a minute. Stop the engine and check the oil level through the transparent oil window on the left side of the engine (fig.
MAINTENANCE 3 - 8 CLUTCH TRANSMISSION CYLINDER ON THE ENGINE Removal Place a clean receptacle under the clutch guard on the right of the engine. Remove the clutch transmission cylinder from the clutch cover (fig. 40). Be careful not to spill any hydraulic liquid on painted surfaces or plastic or rubber parts.
ENGINE REMOVAL - INSTALLATION 5 - 1 Working procedures All operations must be carried out in a clean environment. After disassembly of the parts, wash all components in kerosene or other solvent (never use petrol) and blow dry with compressed air. Carbon deposits are removed with a brush having brass bristles or a scraper with chamfered corners.
ENGINE REMOVAL - INSTALLATION 5 - 1 Remove the engine to frame top mounting bolts; remove the support (figs. 4 - 5). Remove the lower engine bolt (fig. 6). Remove the other engine bolts. Loosen (but don’t remove) the two fork bolts, to allow easier engine removal.
GENERATOR - TIMING BELT - GEARBOX SELECTOR 6 - 1 DISASSEMBLY Remove generator cover mounting bolts together with stator and remove cover (fig. 1). Remove the timing belt cover; loosen idle roller nut and position the idle roller in such a way as to permit the belt to come off the cam pulleys (fig.
GENERATOR - TIMING BELT - GEARBOX SELECTOR 6 - 2 REASSEMBLY Reassemble all components in reverse order of disassembly; pay close attention to the following: Replace the block’s left side cover gasket and the O-ring found behind the final drive pinion. Mount the pinion mounting bolt spring washer, of the freewheel starter group and generator rotor, with the convex side facing out.
CYLINDER HEAD VALVETRAIN COMPONENTS 7 - 2 DISASSEMBLY Pull off the water passage coupler mounted on the right side of the head and remove the O-ring found under the coupler fitting (fig. 1). Remove timing belt cover; loosen idle roller nut and position the idle roller in such a way as to permit the belt to come off the two cam pulleys (fig.
CYLINDER HEAD VALVETRAIN COMPONENTS 7 - 3 INSPECTION After a thorough cleaning of all parts, place the components on the bench and inspect them carefully. All those parts that show signs off wear and/or damage must be replaced. Head Scrape the surface and remove traces of head gasket and remove all carbon deposit in the combustion chamber.
CYLINDER HEAD VALVETRAIN COMPONENTS 7 - 4 REASSEMBLY Assemble in reverse order of disassembly. Pay close attention to the following points: Every component must be installed in the same position before it was removed. This is most important for rocker arms, valves, spring retainer and collets.
CYLINDER - PISTON 8 - 2 DISASSEMBLY Remove the head group, gasket and rubber anti-vibration devises, as described in section 7. Remove the water pump, found on the left of the cylinder (fig. 1). Remove the thermostat’s housing on the front of the cylinder (fig. 2). Lift the cylinder by hand.
CYLINDER - PISTON 8 - 2 Piston rings The rings are removed only when necessary. These components are very fragile and must be removed and installed very carefully. To check for ring wear, take each ring and place it “squarely” inside the lower part of the cylinder.
CLUTCH - PRIMARY DRIVE - OIL PUMP 9 - 2 DISASSEMBLY Drain the oil. Loosen the kick starter bolt; remove cover plate mounting screws and remove right side cover of the engine block. Remove the seeger ring and the thrust bearing (fig. 1). Block the drive gear of the primary drive with special tool 19.1.20515.
CLUTCH - PRIMARY DRIVE - OIL PUMP 9 - 3 REASSEMBLY Assemble in reverse order of disassembly. Pay close attention to the following points: The crankshaft thrust ring is installed with the grooves facing out and it’s notch in the cover’s seat. When mounting the balance shaft, align it properly.
CRANKCASE - GEARBOX - CRANKSHAFT COMPONENTS DISASSEMBLY Make sure all necessary components are removed, then remove all bolts that join the two halves of the cases. Open the crankcase and if necessary use a plastic or rubber mallet to loosen it (carefully hit at the joint of the cases and/or at the end of the gearbox shafts).
CRANKCASE - GEARBOX - CRANKSHAFT COMPONENTS INSPECTION After a thorough cleaning of all parts, inspect all components carefully. All those parts that show sign of wear and/or damage must be replaced. Crankshaft The crankshaft must be replaced if found damaged or worn. Connecting rod Install the half bearings and mount the connecting rod cap by tightening the nuts to the proper torque setting (28 to 32 Nm).
CRANKCASE - GEARBOX - CRANKSHAFT COMPONENTS Crankcase Accurately measure the internal diameter of each main journal with a micrometer. Diameter at mounting = 40.030 ÷ 40.046 mm. Once the bearing and main journal internal diameter is known, it is possible to calculate the gap of the two components. Clearance at mounting = 0.030 ÷...
WORKING PROCEDURES All operations must be carried out in a clean environment. After disassembly of parts, wash all components in kerosene or other solvent (never use petrol) and blow dry with compressed air. All operations must be carried out in a precise order; mark all components to be removed one at a time, or place them in separate containers so as to mount them in the same position as prior to disassembly.
FRONT WHEEL SUB INDEX Section - Page Diagram 12 - 1 Disassembly 12 - 2 Reassembly 12 - 3 Technical data 12 - 3 Trouble shooting 12 - 4...
FRONT WHEEL DISASSEMBLY Disconnect speedometer cable. Loosen the spindle retainer bolts on the right leg. Loosen and slide out wheel spindle with a pin (fig. 1) Remove the wheel. Don’t actuate the front brake lever once the wheel is removed, otherwise it’ll be difficult to insert the brake disc between the brake pads on reassembly.
FRONT WHEEL Bearing disassembly Remove the speedometer drive and drive gear dust cover ring (fig. 6). Remove the wheel bearings and spacer bush from the wheel hub. Do not reinstall the old bearings; once the bearings are removed, they must be replaced with new ones. Bearing reassembly Fill bearing cavity with grease.
FRONT WHEEL REASSEMBLY Place calliper on brake disc, being careful not to damage the pads. Clean wheel spindle and mount it. There are no spindle thrust or spacer washers. Tighten the spindle to the recommended torque, then connect cable to the speedometer drive.
FRONT WHEEL TROUBLE SHOOTING Stiff steering: Steering bearing adjusting ring nut too tight. Faulty steering sleeve bearings. Tyre pressure too low. Tends to steer to one side and has poor handling: Bent front forks. Bent front wheel spindle. Wheel not mounted properly. Different quantity of oil in the two fork legs.
SUSPENSION - STEERING REMOVAL Remove the fairing’s two side mounting screws; remove the side view mirrors mounting screws and remove the mirrors. Disconnect the front turning signal wires and remove the fairing. Remove the front wheel. Loosen the bolt’s safety screws of the semi-handlebars (fig. 1). Loosen the handlebar’s fastening bolts (fig.
SUSPENSION - STEERING Pull out the stanchion and damper piston. Be careful not to confuse the left leg’s piston and other components with those of the right because they’re not interchangeable. Left fork (fig. 6). Right fork (fig. 7). Stanchion inspection Place the stanchion on V-shaped supports and check for straightness error (fig.
SUSPENSION - STEERING - 13 Fill each stanchion with the correct amount of damping oil. Inspect the fork plug’s O-ring and replace if necessary. Install the fork tube spring with the narrow spiral facing up. Right fork component reassembly (figs. 11-12). Left fork component reassembly (figs.
REAR SUSPENSION AND WHEEL TECHNICAL DATA Wear limit Centering error 2.0 mm Rear wheel spindle runout 0.20 mm TROUBLESHOOTING Motorcycle oscillations and vibrations Deformed rim. Loose wheel bearings. Defective tyre. Wrong tyre pressure. Chain adjustment eccentrics not aligned equally. Suspension too soft Weakened fork springs.
REAR SUSPENSION AND WHEEL Chain sprocket inspection Check sprocket teeth; replace if worn or damaged. Check both the chain and driven sprocket. Sprocket in good shape (fig. 4A). Replace sprocket (fig. 4B). Max. allowable wear (fig. 5). NOTE The sprocket retainer hub (flange) is mounted on the rim. The flexible coupling screws are the same ones that hold the chain sprocket to the flange.
REAR SUSPENSION AND WHEEL Wheel reassembly Place wheel in swing fork and place the spacers (fig. 12). Place chain on sprocket. Insert the spindle in the chain tension adjuster eccentric and push it into the hub. Mount the spindle nut from the other side. Adjust chain tension and tighten the wheel spindle to the correct torque.
REAR SUSPENSION AND WHEEL Remove the uni-ball with the aid of a hydraulic press using special tool 19.1.20566 (fig. 19). Make sure the uni-ball isn’t worn or damaged; replace if necessary (fig. 20). Mount the fork pivot bolt bushing with the aid of a press and the proper mounting tool (fig.
REAR SUSPENSION AND WHEEL FINAL DRIVE Drive chain Chain life depends on lubrication and appropriate tension. Neglecting the above mentioned checks will result in wear and damage of both the drive and driven sprockets thereby compromising motorcycle performance. A chain inspection must be carried out prior to driving off; chain adjustment must be executed every 2,000 km.
BRAKES Section - Page Brake pad replacement 15 - 1 Servicing information 15 - 2 Technical data 15 - 2 Troubleshooting 15 - 2...
BRAKES 15 Fluid draining Connect a tube to the bleeder valve. Loosen the bleeder valve and pump with lever. Stop pumping when no more fluid flows out of the bleeder valve. Brake fluid spilled on discs or pads will reduce braking capability. If this should happen, throw away the pads and clean the disc thoroughly with a proper solvent.
BRAKES Front brake calliper inspection Remove the calliper from the leg. Remove the calliper assembly bolts. Remove the two pistons (fig. 7). If necessary, use compressed air (with short bursts) in the fluid inlet hole to push out the piston. Check cylinders and pistons for scratches and pitting;...
BRAKES SERVICING INFORMATION The brake calliper may be removed without disconnecting it from the hydraulic system. Every time maintenance is performed on the hydraulic system the brakes will feel “spongy,” therefore the system will need to be bled. Avoid foreign matter from getting in the hydraulic system when topping up. Brake fluid will damage painted surfaces.
BATTERY CHARGING CIRCUIT BATTERY VOLTAGE Place, with the engine running, the red lead of the voltmeter on the positive (+) terminal of the battery and the black lead on the negative (-). Charge with battery at rest: 12 ÷ 13 V If the meter shows a reading of under 11 V, check the charging circuit connections.
BATTERY CHARGING CIRCUIT WARNING The electrolyte level must be checked periodically; top up with distilled water if necessary. Remove the battery from the frame when charging. Keep battery away from sparks and flames due to the hydrogen produced by the battery. All charging components may be tested without removal.
BATTERY CHARGING CIRCUIT Rectifier check It is a three-phase rectifier. Check the diode’s efficiency by disconnecting the connector end (fig. 3): Connect the positive (+) prod of the ohmmeter to the red wire and the negative (-) one to the white wires (one at a time) (fig. 4). With efficient diodes, the pointer should not move.
IGNITION SYSTEM DESCRIPTION The ignition system is of the capacitive discharge type. The system is made up of a magneto flywheel, CDI control unit and an HT ignition coil. The voltage generated by the coil is stored in the condenser. The signal generated by the pick-up windings is sent to the control unit that will discharge the current stored in the condenser into the coil’s pri- mary windings;...
IGNITION SYSTEM INSPECTION The whole ignition system may be tested for malfunctions or weak spark with testers. If the electrodes generated a good spark at the recommended gap then the system is functioning; if there is no spark proceed with testing each component until having found the malfunction. Follow the troubleshooting charts until finding the source of the trouble.
IGNITION SYSTEM SPARK PLUG Check spark plug condition; replace if overheated, fouled or worn. Measure electrode gap; clean and adjust if out of specification. The spark plug must be checked every 1,000 km. Electrode gap should be 0.6 ÷ 0.7 mm. Replace plug every 8,000 km. Warning: The use of spark plugs with different heat ranges than recommended or different threads may result in excessive engine damage.
ELECTRIC STARTER Section - Page Starter motor 18 - 1 Casing insulation check 18 - 1 Troubleshooting 18 - 1...
ELECTRIC STARTER STARTER MOTOR Removal The electric starter may be removed with the engine in the frame. Put ignition switch in the “OFF” position and disconnect the battery’s negative (-) cable prior to starter motor maintenance. Disconnect the starter’s cable. Loosen the starter’s mounting bolts and remove the starter.
SWITCHES - HORN - LIGHTS - REAR MUDGUARD - EXHAUST PIPE In order to isolate an electrical problem, always check the continuity in the current path. A continuity check is usually executed without removing the component from the motorcycle; simply disconnect the wires and connect them to a tester connector or ohmmeter.
SWITCHES - HORN - LIGHTS - REAR MUDGUARD - EXHAUST PIPE NEUTRAL SWITCH Disconnect the neutral switch connector. Check for continuity between the wire and ground for each gear selection. The switch is working properly when there is continuity in the neutral position and no continuity in any other gear.
SWITCHES - HORN - LIGHTS - REAR MUDGUARD - EXHAUST PIPE If the fan turns, check the thermoswitch in the following manner: Drain the cooling fluid. Remove the thermoswitch from the radiator. Heat the cooling fluid in a container and suspend the thermoswitch in it. Check the temperature where the switch opens and closes.
SWITCHES - HORN - LIGHTS - REAR MUDGUARD - EXHAUST PIPE TROUBLESHOOTING When ignition switch is in the “ON” position the lights don’t turn on: Faulty or burned bulbs. Defective switch. Open or shorted circuits. Burned fuse. Loose, broken or shorted wires. Battery weak or not connected.
CIRCUIT DIAGRAM Section - Page Circuit diagram 21 - 1 WIRING COLOURS LIST OF ELECTRICAL SYSTEM COMPONENTS Lighting group Light Blue Two level bulb 12V - 45/40W Orange Front parking light bulb 12V - 3W Light Blue/Black White Front and rear turn indicators Dark Blue Blinker bulb 12V - 10W Multiple connectors...
A Gilera tool is available, but you can make do by using a 6mm box spanner for the lock nut, and a screwdriver long enough to work through the middle of the box spanner for the adjuster.
MAINTENANCE TIPS Cables - oiling Clutch and brake cables used to need oiling regularly with engine oil. Modern cables are nylon lined and will work for ages with no attention. When they start to get stiff, lube them with WD40 or similar. Speedo cables may be nylon lined, if they are you should be able to see a plastic tube around the inner cable if you look at the end that goes into the clock.
MAINTENANCE TIPS Steering head races You need to get the front wheel off the ground to check the condition of the bearings. Head races are checked by raising the front wheel off the ground and turning the handlebars slowly from side to side. If you notice a slight ‘notchy’...
MAINTENANCE TIPS Continuation If you have to change the races, the difficult bits are getting the bottom inner race off the stem and getting the outer races out of the steering head. There are tools designed to do the job and a local repair shop MAY lend/hire them to you.