CRF/XR50 - BBR Motorsports
Contents
1. CRF XR50 106cc Stroker Crank Kit Thanks for purchasing this exciting new product from BBR Motorsports Extensive R amp D has gone into this product and we are certain that you will be just as excited about it as we are If you have any questions please give us a call Thanks BBRMOTORSPORTS 1028 4th St SW A Auburn WA 98001 1 888 668 6227 Installation Instructions Tools Required Honda Service Manual 8mm socket wrench or T handle wrench 9mm wrench 10mm socket wrench or T handle wrench Torque wrench Special clutch removal wrench see text Feeler gauges to adjust the valves Disclaimer This big bore kit requires professional installation It is up to you to determine if you have the skills necessary to install this kit If you are not confident in your abilities please contact a profes sional mechanic This kit installs exactly like the OEM Honda compo nents with the exceptions noted here You should refer to the OEM Honda Service Manual for any questions regarding disassembly or reassembly of your motorcycle engine Because BBR Motorsports Inc cannot control the assembly of this engine kit no guarantees are made as to performance reliability or usability It is entirely up to the individual doing the installation to determine the fitness of this product and its usability All liabilities are the responsibility of this individual both consequential and incidental We recommend using high q2. crank 33 Install cam chain and ignition stator base Note At this time you may chose to install motor into the chassis or install after cylinder and cylinder head assembly is installed 34 Piston Ring Installation Using your fingers and a mini mal amount of force pry each ring over the piston and slide it into the groove Apply a thin coat of motor oil onto each ring before installing Install the oil expander ring the wavy ring onto the bottom groove See bottom drawing Install the two thin rings one below the oil expander ring and one above in the same groove Install the black ring onto the center groove making sure any letters face up Install the black and silver ring onto the top groove making sure any letters face up cont 34 cont Rotate all gaps in rings approxi mately 90 degrees from each other so they do not line up Also make sure that the oil expander ring does not overlap itself 35 Install a piston clip into the piston Use your fingers to compress the rings while slid ing the piston into the cylinder Turn the piston so that the IN is facing the carb intake side of the cylinder Let the piston protrude enough to insert the piston pin 36 Make certain that the crank is at top dead center at the top of its stroke or TDC This is indicated by the T on the flywheel lining up with the notch in the case Turn the flywheel to
3. e engine cases The base gasket may also be difficult to release Again a rubber ham mer can be used with care 10 Remove one of the small piston clips from inside the pis ton use a small screwdriver or needle nose pliers Push out the piston pin and remove the piston from the rod Use care not to drop the clip into the en gine cases Place a rag in the engine openings to prevent this 11 Remove kickstarter le ver brake pedal and footpeg mount Remove clutch cover right crankcase cover by re moving the 8 6mm bolts 8mm head 12 Remove the ball retainer and spring Remove the clutch lifter lever 13 Remove oil through tube this is the name of the part and spring Remove the clutch lifter cam plate 14 Remove the 4 Phillips head screws and then remove the clutch outer cover 15 Straighten the tab of the clutch lock nut lock washer Remove the clutch lock nut with the appropriate special clutch tool It is available from Honda as part 07716 0020100 16 Remove the oil pump by removing the 3 Phillips head screws 17 Remove ignition stator base 2 phillips head screws 21 Remove the shiftdrum stop per arm and camplate 1 bolt each 18 Remove camchain tensioner and cam chain 22 Remove the snap ring from the kickstarter shaft disconnect the return spring and slide off the retainer 19 Remove the snap ring retain 23 Remove the shift shaft ing the dri
4. il through spring and oil through tube Next install the spring ball retainer and the clutch lifter arm Fi nally reinstall the clutch cover right side engine case kick starter and brake pedal 51 Adjust the valves Re move the Intake and Exhaust valve cover caps with a 1 mm wrench 52 Using a 9mm wrench loosen the lock nut and rotate the adjuster until your feeler gauge measures as follows Intake 002 Exhaust 003 Lock adjusters and reassemble 53 Install carb manifold and air filter Be sure to oil the air filter with a quality motorcycle air filter oil designed for a cot ton element filter Install throttle and route cable 94 Fill with engine oil and check that everything is tight and in place Typical warm up proce dures as described in your own ers manual should be followed to allow for proper break in
5. mp onto the crankcase while aligning the pump shaft groove with the pump drive shaft Install and tighten the 3 Phillips head screws that secure the oil pump 41 Check that the crank is still at TDC Camshaft lobes should be pointing down Insert the tim ing chain sprocket and align the O on the top of the sprocket with the notch in the cylinder head It may be helpful to use a screwdriver to hold the sprocket from dropping into the engine 45 Disassemble the clutch basket by pressing on the plates on the back side and releasing the large snap ring with a screw driver 46 Remove the 4 Phillips head screws on the front of the clutch basket 47 Pull the outside of the basket off exposing the clutch springs Note that the 4 small buffer springs will fall out Re place the clutch springs with the BBR HD clutch springs Reas semble the clutch 48 Once the clutch is assem bled you can insert the clutch buffer springs from the front side Insert the back of the spring into the cast iron inner basket Use a screwdriver to compress the spring and slip it into the out basket s tang 49 Reinstall the clutch assem bly onto the crankshaft Install the 14mm tabbed lock washer then the conical lock washer with the words OUT SIDE facing out and then the lock nut Use the special clutch tool to torque the nut to 12 1 5ft lbs 50 Install the clutch lifter cam plate the o
6. position the crank at TDC if necessary 37 Slide the cylinder onto the engine after placing the gasket o ring and dowels onto engine cases Once the piston has reached the connecting rod install the wrist pin through the piston and install the 2 circlip to secure the piston pin 38 Feed the timing chain up through the cylinder and install the 6mm bolt 10mm head to retain the cylinder to the engine cases Slide the timing chain roller into the cylinder and in Stall its bolt 42 Once the sprocket has been installed double check that the flywheel is on the T mark and the notch on the cyl inder head is pointing at the O on the sprocket Torque bolts to 6 5 ft los Rotate the flywheel slowly by hand and check for any interference 39 Slide the head gasket onto the head studs and install the o ring Asmall amount of grease on the o ring can help hold it in place Then slide the cylinder head onto the head studs Feed the timing chain up through the cylinder head 43 Install the cam cover IMPORTANT NOTE If you do not correctly orient the timing sprocket major engine damage will occur If you are unsure about this procedure seek ad vice from a qualified mechanic 40 When installing the top cyl inder head cover make sure the arrow on the cover is pointing down Place the copper washer onto the bottom left bolt Place the plain nut onto the bottom right bolt 44 Install new oil pu
7. uality motorcycle oil and changing it often 1 Removal of cylinder head and cylinder can be done with the motor in the chassis or re 5 Remove the 4 10mm nuts from the top of the cylinder head cover and remove the cover air filter assembly carb drive chain skidplate exhaust sys tem and shift lever 2 Remove the left side cover flywheel cover by removing amp the 3 6mm bolts 8mm heads gt 6 Remove the camshaft sprocket from inside the left of the cylinder head by removing Remove countershaft sprocket its 2 6mm bolts 8mm heads 3 Remove the left side timing chain camshaft cover by remov ing the 6mm bolt 10mm head on the right side of the engine This bolt extends through the camshaft and secures the cam shaft cover mw 4 7 Remove the cylinder head PP gasket and 2 dowels Some f m force may be required to release the head gasket Arubber ham mer may be useful Be careful not to damage the cylinder or cylinder head DO NOT use a screwdriver to pry the compo Ro nents apart or damage will occur HE 4 Remove the 3 6mm bolts 10mm heads that hold the timing chain roller shown and the cylinder head to the cylinder and the cylinder to the engine cases 8 Remove the cam chain roller from inside the cylinder by removing the 6mm bolt 10mm head Needle nose pliers may be helpful to remove the roller from inside the cylinder 9 Remove the cylinder from th
8. ven gear and remove gear ij 24 Loosen and remove the 20 Remove primary gear bush 43 crankcase bolts 7 ing and spacer These parts will need to be installed on your new crank 25 Place the engine left side down on supports old 2 X 4 s work well Separate the right and left crankcase halves May help to tap transmission shaft and crankshaft with rubber hammer 26 Remove the crank 27 Clean the crankcase mating surfaces before assembling 28 Install BBR crank into left crankcase 29 The oil passage for the new high flow oil pump needs to be drilled to a larger hole size Begin by removing the lower left stud You can use two of the cylinder nuts locked against each other to unthread the stud from the cases With the stud removed use the supplied 2mm drill bit to drill out the oil pas sage Be very careful to protect the internal areas of the engine from stray metal chips when drill ing Be certain to clean up all metal chips before reassembly Reinstall the head stud removed above Install the centercase gasket and install the right crankcase half over the crankcase 30 Install the 7 bolts that hold the crankcase halfs together Tighten in a crisscross patern 31 Install the kickstart shaft with spring into the right side of the motor 32 Install the bolt and washer on the shiftdrum Install drive gear Install primary gear bush ing and spacer removed from OEM
Download Pdf Manuals
Related Search