Our Winter project bike is coming together nicely. To recap, we started out with a 1997 Yamaha YZ125 that had a blown engine and had been left abandoned outside for several years. We started out by completely disassembling the bike down to the last nut and bolt. The frame was sent off to be repainted ( Lexus silver ). While that was off we rebuilt the shock linkage and swing arm pivot with Moose Racing bearing kits. Linkage lubrication is done with Bel-Ray Assemble Lube. NOTHING works better for keeping the linkage working properly. The steering head bearings were replaced. Both front and rear wheel bearing have been replaced. As well as tires, IRC Heavy Duty racing tubes and rim locks. Both Brake calipers and master cylinders have been rebuilt using Moose Racing rebuild kits. Reassembly has begun with the swing arm back on the frame and both suspension units ( front fork & rear shock ) are back on for mock up. They will be gone through before final assembly. UFO plastics replace the weathered stock parts. UFO plastics fit just like OEM parts and hold up better. A new UFO Chain slider and rear chain guide wear block along with new chain rollers are installed. The Stock aluminum rear sprocket
was replaced with a longer lasting and stronger JT Racing steel sprocket for off-road racing. The stock wheel had one rim lock installed, but a second one was added for extra flat prevention and to help hold the tire on the rim in the event of a flat. IMS foot pegs replace the stockers for additional rider comfort.As each system and part is carefully reassembled, lubed and adjusted, everything is tested for proper operation. Insuring that when this bike is ready for racing it will be better then a brand new bike off the showroom floor.
Special attention is being paid to handlebar and brush guard selection for rider comfort and durability. Answer Protaper Contour bars are being used for strength as well as Answer Protaper grips. A new front tire along with IRC Heavy Duty racing tube is installed. Extra special attention has been paid to the front brakes. New EBC pads and EBC brake fluids help increase stopping power along with proper servicing and adjustment of the front caliper alignment. Paying special attention to the small details is what makes the difference between an average bike and one that has been set up for racing.
Assembly of the remaining body work, seat foam, seat cover and graphics can proceed as the engine is being serviced. Last time we showed the how crank assembly was finished. We installed a new rod assembly and bearing. Now we have the cylinder out being re-chromed as the lower end is being reassembled. New crank bearings , crank seals, engine gaskets and seals are being used in the reassembly process of the YZ125 engine continues.
Next time -
-Final engine reassembly
-Systems check and adjustment
-Carburetor and Exhaust
