How do you rebuild a cr500 motor?

Answer 1

Two stroke engines are very easy to rebuild. The transmission component is not. The typical rebuild of a two stroke engine consists of removing the cylinder and replacing parts on the piston assembly. Before you order any parts, inspect the cylinder wall for wear and marking. If the cylinder is damaged you will need to get it machined and then order an oversized piston and ring to go with it. If its not damaged, order a standard (or performace) top end rebuild kit wich comes with a piston, piston ring, piston pin, piston pin bearing, and gaskets. So, for your standard rebuild of the top end you would remove one of the snap rings on either side of the piston pin. This will allow you to push the piston pin out from the opposite side. Once the pin is out the piston will come off the connecting rod. Take note of the piston orientation for assembly. The piston pin bearing will now be accessable (you will find on the connecting rod where the piston pin attached the piston). Minor assembly of the piston prior to installation makes it a bit easier to assemble. Place the piston ring on the piston and align the gap with the small pin you will see in the ring groove (turn the piston ring until it falls into place). Install 1 of the snap rings in the piston where the piston pin slides through it. The piston is now prepped for installation. Place the new piston pin bearing in the connecting rod with some assembly grease to hold it. Place the new piston onto the connecting rod so the hole in the piston matches the hole on the connecting rod. Slide the piston pin through the piston, connecting rod, and into the other side of the piston until it contacts the snap ring you installed earlier. Install the last snap ring into the piston to hold the pin in place, cover the outsides of the piston in assembly grease and lower the cylinder onto the piston. If you don't have a piston ring compressor you can hold the piston ring tight to the piston with your fingers. If you encounter any resistance when your putting on the cylinder you can LIGHTLY press the piston ring into the piston with a small slot-head screwdriver. Once that is together you should look up the torque specs for your make/model or if your not that picky just tighten them up at your discretion. If your looking to do anything on the bottom end of the motor or in the transmission I would HIGHLY recommend getting it done at a shop. Unless you know what you are doing you will have a puzzle of gears and springs to put back together.