ktm sx65 carburetor float level check adjustment

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Lambretta UNO50 Owners Manual

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Filed Under (Lambretta) by admin on 25-11-2010

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brakes: Inspect brake cables/hoses/linkage for correct mounting, chafing, leaks and damage. Check and adjust both front and rear brakes. If hydraulic, check fluid level and correct if necessary (DOT 4 fluid only). Engine: Check and correct the engine oil level. Fuel system: Check fuel tank, carburetor, fuel valve and all hoses for leaks. Throttle system: Check for correct throttle cable routing. Throttle operates smoothly and self-returns to idle from all handlebar positions. Wheels/tires: Check wheels, tires and valve stem for damage, etc. Check and adjust tire pressures. 11 Suspension: Check for smooth suspension operation. Lubricate all grease points using correct specification grease. Check for correct suspension adjustments. Inspect fork and shock seals for leaks. Steering: Check for smooth steering operation and handlebar bearings for proper adjustments. Electrical Systems: Check for correct function of all side, headlight (high/low beam) and taillights, turn indicators, brake lights, warning lights and instrument illumination. Check for correct horn operation. Check harnesses for correct routing. Check for correct function of starter lockout system. Check for correct engine stop switch operation. Check for correct function of the low oil warning light. (2 stroke only) Emission Systems: Check connections and hoses for routing and kinks.
12 Fastening hardware: Check front and rear axle nut and bolt torque. Check torque of drain plug and oil filter bolt. Check torque of all brake system nuts and bolts. Check torque of all steering system mounting hardware. Check torque of exhaust mounting hardware. Check torque of all remaining nuts, bolts & screws. Road test Front and rear brake operation. (approx. 10km): Check cold engine start performance. Evaluate performance, handling and braking. After road testing: Check hot engine starting. Check and adjust idle speed. Check for oil and fuel leaks. Make necessary adjustments and repair any defects seen or observed before, during and after test drive. Retest as necessary. Clean the vehicle prior to deliver

KTM 60 SX / 65 SX REPAIR MANUAL ENGINE

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Filed Under (KTM) by admin on 12-11-2010

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Carburetor adjustment Basic information about the original carburetor setting The original carburetor setting was adapted for an altitude of approx. 500 meters (1600 ft.) above sea level, and the ambient temperature of approx. 20°C (68°F), mainly for off-road use and central European premium-grade fuel (ROZ 95). Mixing ratio 2-stroke motor oil : super fuel 1:40 . Basic information of changing the carburetor setting Always start out from the original carburetor setting. Essential requirements are a clean air filter system, air-tight exhaust system and an intact carburetor. Experience has shown that adjusting the main jet, the idling jet and the jet needle is sufficient and that changes of other parts of the carburetor will not greatly affect engine performance. RULE OF THUMB: high altitude or high temperatures  choose leaner carburetor adjustment low altitude or low temperatures  choose richer carburetor adjustment * WARNING * -ONLYUSE PREMIUM – GRADE GASOLINE ROZ 95 MIXED WITH HIGH – GRADE TWO – STROKE ENGINE OIL . OTHER TYPES OF GASOLINE CAN CAUSE ENGINE FAILURE , AND USE OF SAME WILL VOID YOUR WARRANTY . -ONLYUSE HIGH – GRADE 2- STROKE ENGINE OIL OF KNOWN BRANDS ( I . E .SHELL ADVANCE RACING X). -NOTENOUGH OIL OR LOW – GRADE OILCAN CAUSE EROSION OF THE PISTON . USING TOO MUCH OIL , THE ENGINE CAN START SMOKING AND FOUL THE SPARKPLUG . -INTHE CASE OFA LEANER ADJUSTMENT OF THE CARBURETOR PROCEED CAUTIOUSLY . ALWAYSREDUCETHEJETSIZEINSTEPSOFONENUMBERTOAVOID OVERHEATING AND PISTON SEIZURE . NOTE: If despite a changed adjustment the engine does not run properly, look for mechanical faults and check the ignition system. Basic information on carburetor wear As a result of engine vibrations, throttle valve, jet needle, and needle jet are subjected to increased wear. This wear may cause carburetor malfunction (e.g., overly rich mixture). Therefore, these parts should be replaced after 1000 hours of using. Idling range – A Operation with closed throttle valve. This range is influenced by the idle adjusting screw 1 . Only make adjustments when the engine is hot. The idling speed can be changed by turning the idle adjusting screw. Turning it clockwise produces a higher idling speed and turning the screw counterclockwise produces a lower idling speed. Opening up – B Engine behavior when the throttle opens. The idle jet and the shape of the throttle valve influences this range. If, despite good idling-speed and part-throttle setting, the engine sputters and smokes when the throttle is fully opened and develops its full power not smoothly but suddenly at high engine speeds, the mixture to the carburetor will be too rich, the fuel level too high or the float needle is leaking. Part-throttle range – C Operation with partly open throttle valve. This range is only influenced by the jet needle (shape and position). The optimum part-throttle setting is controlled by the idling setting in the lower range and by the main jet in the upper range. If the engine runs on a four-stroke cycle or with reduced power when it is accelerated with the throttle partly open, the jet needle must be lowered by one notch. If then the engine pings, especially when accelerating under full power at maximum engine revs, the jet needle should be raised. If these faults should occur at the lower end of the part throttle range at a four-stroke running, make the idling range leaner; if the engine pings, adjust the idling range richer

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POLINI X1 GENERAL INFORMATION AND SPECIFICATIONS

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Filed Under (Polini) by admin on 02-12-2010

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Air cleaner – Clean and reoil daily or after each moto to prevent motor failure and reduced performance. Transmission oil – change after every race, or at end of riding day. Chain – check tension and lubricate before every ride, adjust or replace as needed. Reoil after riding in damp conditions. Clutch – disassemble and clean clutch assembly frequently, every 2-3 races at least. Inspect kickstarter gears at this time. Ignition cover – remove cover and wipe dry after each ride or after washing bike to remove condensation. Piston rings – replace as often as every 3-5 races with expert rider, less often with less aggressive riders. Piston, pin, rod bearing & circlips – replace as often as every 8-10 races with expert rider, less often with less aggressive riders. Coolant – change yearly, make sure there is at least a 50/50 mixture of antifreeze if freezing temperatures are possible. Steering bearings – Check daily for looseness or play. Adjust and regrease as needed. Swingarm – Check often for looseness. Regrease several times a year. Replace bushings if any play is evident. Sprockets – check for worn or curved teeth each time chain is adjusted. Chain roller& wear pads – check roller for free rotation when checking chain. Make sure roller is not bent or damaged. Check chain wear strips on swingarm and chain guide frequently. Replace as needed to prevent chain from damaging motorcycle. Spokes – Check after each race or after each day of riding for looseness or damage. Wheels & tires – check wheels after each race for dents, cracks or other damage. Check tires for cuts, damage or wear. Check tire pressure daily and adjust for riding conditions. Shock – Check shaft area daily for signs of oil leakage or damage. Check swingarm and shock bushings for looseness. Forks – Check forks daily for leaking oil or damage to tubes. Make sure forks are not twisted check for smooth operation. Spark plug – check sparkplug color and condition after each race or end of riding day. Adjust jetting to keep plug from fouling or overheating. Silencer – If bike seems to be getting louder, replace packing and decarbonize inner tube. Expansion pipe – check daily for large dents, damage or leakage. Remove carbon from headpipe when pipe is removed. Have large dents fixed, or any dents within 8″ of the cylinder. Replace o-rings on pipe as needed to maintain a good seal. Footpegs – check daily for proper operation, pegs should spring back into place. Make sure pegs are not bent or overly dull. Handlebars – check bars after any crash for bending. Look for cracks near bar clamps. Replace bars that have been straightened more than 2 or three times, or if bar is badly bent. Aweakened bar can snap suddenly causing injury to rider. Throttle – check throttle for proper operation each time before bike is started. Remove and clean inside of grip and bar as needed. Grips – check grips daily for wear or looseness. Replace as needed. Use grip glue & safety wire to help hold grips in position. Calipers & pads – check pad wear and caliper function daily or after each race. Replace pads and clean calipers as needed. Brake lever – check lever daily for damage or wear. Make sure lever is at proper angle for both seated and standing positions. Leave lever clamp loose enough to allow clamp to rotate during crash rather than breaking lever. Check and adjust freeplay as needed. Brake pedal – Check pedal daily for damage and proper freeplay. Adjust rear caliper as needed. Reeds – Remove and inspect reed block during every ring change. Check reeds for signs of wear, fraying and cracking. Make sure reeds sit flat and seal well. Replace at any sign of wear or damage or at least once a year, more often for expert riders. Nuts & bolts – Check all nuts and bolts regularly. Make sure to check engine mounting bolts and swingarm bolt frequently

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HONDA CT110 OWNERS MANUAL

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Filed Under (Honda) by admin on 22-04-2011

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ENGINE OIL Engine Oil Level Check Check the engine oil level each day before riding the motorcycle. The level must be maintained between the upper (2) and lower (3) marks on the dipstick (1). 1. Start the engine and let it idle for a few minutes. 2. Stop the engine and hold the motorcycle in an upright position on firm, level ground. 3. After a few minutes, remove the oil filler cap/dipstick, wipe it clean, and reinsert the dipstick without screwing it in. The oil level should be between the upper and lower marks on the dipstick. 4. If required, add the specified oil up to the upper level mark. Do not overfill. 5. Reinstall the oil filler cap/dipstick, check for oil leaks. CAUTION Running the engine with insufficient oil can cause serious engine damage. TYRES Proper air pressure will provide maximum stability, riding comfort and tire life. Check tire pressure frequently and adjust if necessary. NOTE Tire pressure should be checked before you ride while the tyres are cold. Select the right replacement tire in accordance with the following specifications: Cold tire pressures kPa ( kg/cm2, psi ) Front: 175 ( 1.75, 25 ) Rear : 225 ( 2.25, 33 ) Tire size Front: 2.75 – 17 41P Rear : 2.75 – 17 41P Check the tires for cuts, embedded nails, ore other sharp objects. See your authorized Honda Dealer for replacement of damaged tires or punctured inner tubes OPERATION PRE-RIDE INSPECTION WARNING If the Pre-ride Inspection is not performed, serious damage or an accident may result. Inspect your motorcycle very day before you ride it. The items listed here will only take a few minutes to check, and in the long run they can save time, expense and possibly you life. 1. Engine oil level – add engine oil if required. Check for leaks. 2. Fuel level – fill the fuel tank when necessary. Check for leaks. 3. Brakes – check operation. Adjust free play if necessary. 4. Tyres – check condition and pressure. 5. Drive chain – check condition and slack. Adjust and lubricate if necessary. 6. Throttle – check for smooth opening and full closing in all steering positions. 7. Lights – check that headlight, tail/brake light, turn signals, indicators. 8. Engine stop switch – check for proper function. 9. Battery electrolyte – check the level and add if necessary Correct any discrepancy before you ride. Contact your authorized Honda dealer for assistance if you cannot correct the proble

HARLEY DAVIDSON LCD OIL TEMPERATURE/ LEVEL DIPSTICK INSTALLATION INSTRUCTIONS

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Filed Under (Harley Davidson) by admin on 01-02-2011

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LCD DIPSTICK INSTALLATION 1. Remove the original equipment (OE) dipstick from the filler neck. 2. Non-threaded Dipsticks: Lightly oil the O-ring on the new LCD dipstick. Orient the dipstick so that the display window is horizontal and readable from left to right, with the Bar and Shield logo to the left (towards the rear of the motorcycle). Push the dipstick straight into the filler neck until it seats. 3. For threaded dipsticks: Lightly oil O-ring and screw into the transmission like OE dipstick. If the orientation of the display is unsatisfactory when fully seated, refer to Adjusting the Display Angle later in these instructions. NOTE To be sure of correct readings, the dipstick MUST seat firmly against the flange. LCD DIPSTICK USE AND CARE Removing the Dipstick The dipstick assembly must be removed from the filler neck to add oil or to service the internal battery. Displaying the Oil Temperature and Level See Figure 1. Press and release the rubber button on the front face to display the temperature of the oil in the oil tank in degrees Fahrenheit (°F), and the oil level. The display will automatically shut off after approximately ten seconds. Do not overfill oil tank. Doing so can result in oil carryover to the air cleaner leading to equipment damage and/or equipment malfunction. (00190a) NOTES Oil level cannot be accurately measured: • on a cold engine • with the motorcycle upright • with the engine running NOTE Oil level on 2000 through 2004 Softail models with the original dipstick is checked with the motorcycle standing upright (not leaning on the jiffy stand). THIS IS NOT THE CASE with the LCD oil temperature/level dipstick. For all 2000 and later Softail models, oil level inspection must be done with the motorcycle LEANING ON the jiffy stand, on level ground. For pre-ride oil level inspection: With the motorcycle on level ground, RESTING ON the jiffy stand : •The oil level should be as indicated in Figure 1, display 4 through 8 (bars showing oil level, and “COLD OIL” message followed by flashing oil temperature) when the engine is cold. DO NOT ADD OIL to bring the level to the FULL mark on the dipstick of a COLD engine. •If the oil level indicates as in display 9 (animated level bars, followed by an “888 NO SENSOR” code), the wires inside the dipstick may be disconnected or damaged. Refer to Replacing the Battery later in these instructions to separate the dipstick upper and lower assemblies. If the small plug next to the battery has become dislodged from the receptacle, plug it in. If a visible wire is damaged, a repair can be attempted. If no damage is visible, the dipstick is damaged internally and should be replaced. For oil level inspection at operating temperature: Ride the motorcycle until the engine is at normal operating temperature. Idle for 1-2 minutes with the motorcycle on level ground, RESTING ON the jiffy stand (except Softails) , turn the engine OFF.

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YAMAHA XS650H/ SH Supplementary Service Manual

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Filed Under (Yamaha) by admin on 21-11-2010

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Ignition timing check 1. Ignition timing is checked with a timing light by observing the position of the rotor pointer and the marks stamped on the timing plate. The timing plate is marked as follows. “ll” Firing range for No. 1 (L.H.) “T” Top Dead Center for No. 1, fL.H.1 cylinder 2. Connect the timing light to the left cylinder spark plug lead wire. 3. Start the engine and keep the engine speed as specified. Use a tachometer to check the engine speed. B. PICK-UP COIL ASSEMBLY The method of mounting the pick-up coil assembly is changed for easier service work. Thus, the followings “Pick-up coil assembly removal” and “Pick-up coil assembly reinstallation” should be changed. Pick-up coil assembly removal Remove the pick-up coil securing screws and remove the pick-up coil assembly. Pick-up coil assembly reinstallation Install the pick-up coil assembly on to the stator assembly. _ L 4. Specified engine speed: 1,200 r/min The rotor pointer should be within the limits of ” fl ” on the timing plate. If it exceeds the limits or does not steady, check the timing plate for tight- ness and/or ignition system for damage. NOTE: Ignition timing is not adjustable. C. FUEL LEVEL The carburetor is furnished with a drain screw to provide easy access to service work. Thus, the following “Fuel level measurement” should be added. Fuel level measurement NOTE: Before checking the fuel level, note the follow- ing: 1. Place the motorcycle on a level surface. 2. Adjust the motorcycle position by placing a suitable stand or a garage jack under the engine so that the carburetor is positioned vertically. 1. 2. Connect the level gauge (special tool) or a vinyl pipe of 6 mm (0.24 in) in inside diameter to the float bowl nozzle left or right side carburetor. Set the gauge as shown and loosen the drain screw 3. Start the engine and stop it after a few minutes of run. This procedure is neces- sary to obtain the correct fuel level. NOTE: Make sure the fuel petcock is “ON” or “RES” oosition. 4. Note the fuel level and bring the gauge to the other end of the carburetor line and repeat step 3 above. Note the fuel level again and compare it with the previous gauge reading. They should be equal. If not, place a suitable size of wooden piece or the. alike under the center stand and adjust. 5. Check the fuel level one by one. The level should be in the specified range.

KTM 250/ 300/ 380 SX,MXC,EXC ENGINE REPAIR MANUAL

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Filed Under (KTM) by admin on 12-11-2010

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Repair manual KTM 250 / 300 / 380 Art No 3206004 -E 2-2C main jet jet needle jet needle air control screw idle adjusting screw idle jet throttle valve Idling range A Operation with closed throttle valve. This range is influenced by the position of the air control screw 1 and the idle adjusting screw 2 . Only make adjustments when the engine is hot. To this end, slightly increase the idling speed of the engine by means of the idle adjusting screw. Turning it clockwise produces a higher idling speed and turning the screw counterclockwise produces a lower idling speed. Create a round and stable engine speed using the air control screw (basic position of the air control screw = open by 1.5 turns). Then adjust to the normal idling speed by means of the idle adjusting screw. Opening up B Engine behavior when the throttle opens. The idle jet and the shape of the throttle valve influences this range. If, despite good idling-speed and part-throttle setting, the engine sputters and smokes when the throttle is fully opened and develops its full power not smoothly but suddenly at high engine speeds, the mixture to the carburetor will be too rich, the fuel level too high or the float needle is leaking. Part-throttle range C Operation with partly open throttle valve. This range is only influenced by the jet needle (shape and position). The optimum part-throttle setting is controlled by the idling setting in the lower range and by the main jet in the upper range. If the engine runs on a four-stroke cycle or with reduced power when it is accelerated with the throttle partly open, the jet needle must be lowered by one notch. If then the engine pings, especially when accelerating under full power at maximum engine revs, the jet needle should be raised. If these faults should occur at the lower end of the part throttle range at a four-stroke running, make the idling range leaner; if the engine pings, adjust the idling range richer. Full throttle range D Operation with the throttle fully open (flat out). This range is influenced by the main jet and the jet needle. If the porcelain of the new spark plug is found to have a very bright or white coating or if the engine rings, after a short distance of riding flat out, a larger main jet is required. If the porcelain is dark brown or black with soot the main jet must be replaced by a smaller one. mixture too rich: too much fuel in proportion to air mixture too lean: not enough fuel in proportion to air 1 2 OPERATING RANGES OF THE CARBURETOR 2-3C Carburetor adjustment Basic information on the original carburetor setting The original carburetor setting was adapted for an altitude of approx. 500 meters (1600 ft.) above sea level, and the ambient temperature of approx. 20°C (68°F), mainly for off-road use and central European premium-grade fuel (ROZ 95 MOZ). Mixing ratio 2-stroke motor oil : super fuel 1:40 – 1:60. Basic information on a change of the carburetor setting Always start out from the original carburetor setting. Essential requirements are a clean air filter system, air-tight exhaust system and an intact carburetor. Experience has shown that adjusting the main jet, the idling jet and the jet needle is sufficient and that changes of other parts of the carburetor will not greatly affect engine performance. RULE OF THUMB:

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HSR Carburetor Total Kits Installation Instructions

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Filed Under (Mikuni) by admin on 31-10-2010

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Intake Manifold: 1. Install MAP sensor in Mikuni manifold (Twin Cam only). 2. Attach the Mikuni manifold to the engine. Align the manifold before tightening the bolts. The flange surface of the Mikuni manifold should be parallel with the front of the engine’s cam cover. Use a level or angle meter to check this. Tighten the manifold bolts. 3. Attach the rubber flange to the Mikuni manifold with the furnished 5/16″x3/4″ bolts and washers. Choke Cables: Mikuni & Harley-Davidson Route the cable with largest radius bends possible. Check the cable for free-play after installation. If there is no free-play, the engine may run rich and deliver poor performance or low fuel mileage. Harley Cable (Twin Cam Kits: 42-19, 45-4) : 1. Remove the Harley choke cable from the stock carb. 2. Remove the spring and plunger from the cable. 3. Remove the spring and plunger from the Mikuni. 5. Install the Mikuni spring and plunger onto the Harley choke cable. Change nothing else; be sure to use the Harley plastic nut, not the Mikuni nut (See Figure 1). Total Kit Installation Instructions The HSR series carburetors are precise yet durable instruments; however, like any other piece of fine equipment, they require correct installation and reasonable care to assure optimum performance and long life. Extra time spent during installation will pay off in both short and long term performance and reliability. This Mikuni HSR carburetor kit is designed to be a bolt-on application, and as such, is set-up and jetted properly for most applications. However, since Harley-Davidson motors are often highly modified, alternate tuning settings may be required. The Mikuni Tuning Manual helps make jetting alterations and adjustments an easy matter. NOTE: Carburetor Kits not designated as C.A.R.B. exempt, are not legal for motor vehicles operated on public highways in the state of California, or in any other states and countries where similar laws apply. WARNING NOTE: NOTE: WARNING CAUTION NOTE: NOTE: TK-2 6. Install the new assembly into the Mikuni carburetor. Be careful to only gently tighten the plastic nut. 7. Loosen the knurled plastic friction nut behind the choke knob and check for free-play (see Figure 2). Figure 1: Harley nut with Mikuni spring & plunger Figure 2: Choke cable adjustments Mikuni Cable (Evo Kits: 42-8, 45-2 & 45-3) : 1. Remove nut, spring and plunger from the Mikuni. 2. Install the nut, spring and plunger onto the cable. 3. Install the assembly into the Mikuni HSR carburetor. Be careful to only gently tighten the plastic nut. 4. Check for free-play. Adjust the cable as necessary. An optional choke cable mounting bracket is included in the Evo kits for custom installations. Carburetor Installation: 1. Insert the carb fully into the rubber flange, align with engine and tighten the clamp. 2. Slip the fuel hose onto the carburetor’s fuel fitting and secure with the enclosed hose clamp. NOTE: Some Twin Cam installations may require removal of a small amount of fin material from the cylinders to clear the float bowl. Throttle Cables The HSR carburetor uses stock 1990 and later Harley- Davidson cables. However, if your Harley is fitted with some other carburetor, you may need to purchase a set of cables. See your dealer for the correct cable set. 1. Route the throttle cables with large radius curves and so they do not interfere with other components. 2. Screw the cable adjusters together to make them as short as possible. 3. Connect the “close” cable first (see Figure 3). 4. Install the “open” cable next (see Figure 3). 5. Adjust the opening cable until the slide can be opened fully. Snug the adjuster lock nut. 6. Turn the handlebar to the right and adjust the throttle free-play with the closing cable adjuster to approximately 1/8″ (see Figure 4)

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Honda Ct110 Series Engine Oil Level Check

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Filed Under (Honda) by admin on 17-09-2011

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Engine Oil Level Check Check the engine oil level each day before riding the motorcycle. The level must be maintained between the upper (2) and lower (3) marks on the dipstick (1). 1. Start the engine and let it idle for a few minutes. 2. Stop the engine and hold the motorcycle in an upright position on firm, level ground. 3. After a few minutes, remove the oil filler cap/dipstick, wipe it clean, and reinsert the dipstick without screwing it in. The oil level should be between the upper and lower marks on the dipstick. 4. If required, add the specified oil up to the upper level mark. Do not overfill. 5. Reinstall the oil filler cap/dipstick, check for oil leaks.

Triumph Bonneville Tuning Manual

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Filed Under (Triumph) by admin on 20-11-2010

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1. The Float The float bowl acts as a fuel reservoir to meet engine demand. The float is hinged on a pin in the float boss. It rises and falls with the fuel level in the float bowl. The small metal tang integrated in the plastic float supports the float valve, also known as the float needle. As the fuel in the float bowl rises, the float valve is pushed into the valve seat, until it’s high enough to shut off the fuel flow to the bowl. As fuel is used the level in the bowl drops lowering the float which pulls the float valve from its seat, and fills again. Adjusting the height of the float has a big effect on the mixture as a low or high float level makes it harder or easier for the vacuum to suck fuel into the venturi. Differing float levels cause an imbalance which may be perceived as vibration. 2. The Choke This system is referred to as the choke. But that’s a misnomer. When you pull the choke knob, what you’re doing is retracting a plunger that opens a tube connected to the starter jet, allowing additional fuel to enter the venturi just below the vacuum hose nipple. It supplements the pilot system at start up. 3. The Pilot System The primary purpose of the pilot system is to supply the mixture at idle. It continues to supply fuel throughout the entire throttle range, but after about 1/8 throttle is reached the main system starts to put out more of the total mixture, up to full throttle. By adjusting the idle with the big screw on the left side of the carburettors the position of the butterfly is altered, so exposing one or more of the four small holes that are drilled into the venturi, (leading to the pilot jet) just under the butterfly valve, letting more or less air pass the butterfly. Adjusting the pilot screw that’s under the carburettor varies the amount of air premixing with the fuel before it enters the venturi. 4. The Main System Open the throttle and the cable that’s connected to the butterfly valve turns it from vertical to horizontal, so letting more air through the venturi. This increases the vacuum effect that is transferred up through the vacuum drilling in the slide to the diaphragm valve that leads to the diaphragm chamber. The top chamber is separated from the bottom by a rubber diaphragm. The bottom chamber is open to atmospheric pressure from the airbox. When the vacuum in the top chamber rises enough, the constant ambient pressure of the lower chamber helps the diaphragm valve overcome the downward force of the diaphragm spring, so it rises from the ven- turi. As the diaphragm is raised the needle is pulled out of the needle jet, exposing a thinner portion of the needle taper which allows more fuel to rise into the venturi to meet the increased engine demand. The key parts of the main system are shown in the photo below

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