Step 4. Step 3. Watch the clip below to see the timing and valve lash segments of our Honda Grom Big Bore Kit video. We also install a KOSO cam chain tensioner kit to cope with the additional forces from the upgraded motor. Step 2. On small bore street bikes like the Honda Grom and Kawasaki Z125, a big bore kit definitely adds some fun over the underpowered stock engines at the track! If the ring gaps are too small, the ring ends will touch once they heat up in a running engine, which will quickly cause damage to the rings and cylinder. Step 6. Watch the clip below to see the cylinder and piston removal segments of our Honda Grom Big Bore Kit video. Step 5. Step 1. Sell your vehicle through our consignment program! Now that the big bore kit is installed on our Honda Grom and the top end is rebuilt, our next project is to install a larger throttle body, a high-flow air filter, and an upgraded exhaust system. The intake valve gaps should be 0.004” or 0.1016mm. TBparts 186cc Big Bore Performance Kit (64mm) with Performance Camshaft and Race Head by JC Racing with larger bore KOSO intake. Step 3. Remove the circlip and piston pin from the piston, and slide the piston off the connector rod. Step 9. Carefully remove a tiny amount of material from the end of the piston ring if the gap is too small by using a ring end gap grinder to correct the ring gap. Next, remove the two mounting bolts and the throttle body assembly from the engine. Step 2. Take the thermostat from the old cylinder, install it in the new cylinder, and reattach the cable and bracket. Watch the clip below to see the cylinder head installation segment of our Honda Grom Big Bore Kit video. Step 3. We have sold and installed TB products with great success. Then, use a rotor puller to draw the flywheel out of the crankcase. → CHECK OUT our website : http://www.hardracing.com/13-14%20Bikes/14%20GROM.htmHonda Grom Big Bore Kit Installation.- Finbro 183cc BBKPART 1, Introduction to all the parts included in the Honda Grom Big Bore kitMonkey Father Big Bore KitGreat Low Prices→ Subscribe : http://www.youtube.com/user/HardRacingPerformanc?sub_confirmation=1→ Please take a second to leave a comment before you head off.→ Facebook: http://facebook.com/HardRacingLLC → Twitter: http://twitter.com/hardracing_com→ Instagram: http://www.instagram.com/hardracing.#HardRacing #GromBBK #GromBigBoreKit #GromTakegawaBBK #GromKitacoBBK #GromKosoBBK #GromTakegawaBigBoreKit #GromKitacoBigBoreKit #GromKosoBigBoreKit RECOMMENDED ITEMS FROM OUR STORE (not included in this listing), KOSO Performance Throttle Body & Injector System. NOTE: To correctly set the timing and valve lash, the engine must be at TDC. © 2000-2020 Partzilla.com. Reinstall the old cam cover, followed by the timing cap and crankshaft cap into the left side crankcase cover. NOTE: For this project, you’ll need a well-stocked toolbox that includes a ratchet, socket set, wrenches, screwdrivers, a torque wrench and other essential tools, as well as the special tools listed above. Repeat the gap measuring process for the lower piston ring. Step 8. Thoroughly clean the new piston and piston rings with contact/brake cleaner. Install heavy duty valve springs, retainers, seats, and keepers. Elite OEM (Original Equipment Manufacture) Parts Distributor for premium brands! Step 5. Click to share on Facebook (Opens in new window), Click to share on Twitter (Opens in new window), Click to share on Pinterest (Opens in new window), TBparts TBW9150 big bore kit with TBW1050 Camshaft, Port / Flow Cylinder Head with multi-angle valve job, Backcut oversize valves for more flow at all camshaft lifts. Watch the clip below to see the ring gap segment of our Honda Grom Big Bore Kit video. Watch the clip below to see the piston installation segment of our Honda Grom Big Bore Kit video. Remove the cover to the rear of the crankcase cover, followed by the crankcase cover itself. Reinstall the tensioner push rod, the cam chain tensioner spring and the bolt into the crankcase. Step 4. Reinstall the cam sprocket bolt, and torque it to 20 foot-pounds while still holding the crankshaft to prevent it from moving. Install one of the piston circlips into the new piston. Loop the timing chain back over the cam sprocket, and reinstall the cam sprocket with the timing mark aligned with the mark in the cylinder head. Apply a thin layer of grease to the underside of the new cylinder head cap bolts. Install the bolts and washers, and torque the bolts to 18 foot-pounds. This product is legal for closed-course competition use only; for racing vehicles (a competition vehicle not used on public highways). Remove the cam chain guide roller bolt and the chain guide roller. JC Race Head – JC heads start with a basic Honda OEM Cylinder Head core. Honda MSX125 (Grom) Yuminashi 160cc Ultimate Big Bore kit … Reinstall the cam chain guide roller and the washer and pin. The exhaust valve gaps should be 0.007” or 0.1778mm. *WARNING: You must also use an aftermarket fuel controller to prevent a lean condition and damage to your engine. Next, remove the starter reduction gear and its shaft and collar from the left side of the crankcase. The all aluminum ceramic coated cylinder is lighter than a steel sleeved aluminum cylinder, reduces friction (increasing power), improves sealing, and provides better heat transfer (runs and cools down quicker). Take the top piston ring and seat it in the cylinder using the piston. In this video and guide, we fit a KOSO big bore kit, which includes a four-valve head that will increase the cylinder bore to 170cc. Honda MSX125 Grom 2014-2019 and 2019-2020 Monkey 125 Greater performance vs. the KOSO 170cc kit. Watch the video above to see our Honda Grom intake and exhaust installation video. Please have one purchased and installed before your first engine start up. Step 2. You no longer have to piece parts together with expensive components to get more power out of your bike. NOTE: Don’t lose the woodruff key in the crankshaft. Remove the cable and bracket from the thermostat (located in the lower left side of the cylinder) and remove the O2 sensor from the right side of the cylinder head. Kits will vary in size, additi… Remove the bolt from the bottom of the crankcase, followed by the cam chain tensioner spring and the tensioner push rod. Reinstall the two bolts mounting the left side of the cylinder head to the cylinder. ALL Ignition Advance Must be removed from the bike, Prior to running a BBK, or Detonation will occur. NOTE: Work slowly so you don’t damage the new piston, piston rings or cylinder. Reinstall the flywheel, the washer and nut, then hold the flywheel with a sheave holder and torque the nut to 64Nm or 47 foot-pounds. Step 1.