Engine Assembly
Two Stroke Top End Rebuilding
# Start out with a clean workspace.
# First insert the piston rings into the cylinder about an inch down from the top, use the piston to center them into the cyl. Used a feeler gauge to check the ring end gap. check to see that the gap has the required end gap specs. Grinding of the ring ends may be necessary.
Installing Rings & Piston
# Install the rings onto the piston making sure the end gaps line up with the locating pins on the piston. If there is a marking on the rings this needs to be facing upward.
# Next install the piston to the connecting rod, The arrow on the top of the piston usually points to the exhaust side. Always use a new wrist pin, bearing and clips. Put a little 2-stroke oil on the bearing & pin. When inserting the clips make sure that the clips are seated into the grove and the open end of the clip is at the top.
# Take a clean rag and wipe the cylinder wall with new 2 stroke oil until you can wipe the cylinder and have the rag stay clean. Oil has detergents in it and is the best thing to clean metal with. Also that is all the assembly oil you will need. do not sop the piston, ring & cyl. wall with oil. This will only cause you to foul a plug on start up, fill your garage with smoke & cause the cylinder & rings to glaze, giving you poor ring seating and performance.
Cylinder Installation
# Before setting the cylinder on to the piston be sure the base gasket surface is free of any old gasket, dirt grease etc.
# Make sure all dowl pins, o-rings and a new gasket is in place on the engine block.
# Compress the rings using your finger tips or a ring compressor. I prefer not to us the ring compressor.
# A fork shaped tool made from wood can be used to hold the piston into place while sliding the cylinder over the piston.(See Picture)
# When placing the cylinder down over the piston and rings do not twist the cylinder or the rings end gaps may get caught in a port, snagging the rings and bend or break them.
# Do Not force the cylinder down to the gasket with the nuts if it doesn't go down by hand there usually is something wrong!
# If the engine is a twin or triple and has a one piece intake and exhaust manifold, the manifolds should be installed and snagged down before the cylinder nuts are torque to prevent the manifolds from cracking.
Head Installation
Make sure the gasket surface is clean. Make sure all dowl pins & o-rings are in place, install a new gasket making sure and "this side up" markings are facing up.
# Now torque all cylinder & head nuts with a criss cross pattern, starting at 10% of the recommended torque specs. Then going to 50% then your final torque.
# Now install all carbs,(Carbs jet should always be check for correct size and that they are clean) exh. head stays, motor mounts etc.
# Put new coolant in machine.
# If machine has set for more than a month I recommend putting a fresh gas\oil mix in tank. (see our lubrication page for recomended oils & mixtures.
# If machine is oil injected you must bleed all oil lines making sure there is no air bubbles in the lines. Mix the first tank of fuel with a 50:1 oil mix along with the oil injection in case there are air in oil lines. Be sure oil pump cables are connected and adjusted.
# Now you want to review our "Engine break in page" for initial engine start up and break in.
 Wiseco Pistons |
| LA. Sleeve |
| Pro X Pistons |
| Cometic gaskets |
| Marshall Distributing |
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