Our boring machine will take any Norton twin non-spigoted cylinder which includes the later Atlas cylinder and all the 750cc and 850cc Commando cylinders. If you are not purchasing new pistons from us, you will need to send us your pistons along with the cylinder so we can set the proper skirt clearance. We normally set the skirt clearance between .004" to .005", if your piston manufacture suggest a different skirt clearance, please provide us with that information so we can set the proper clearance. The cylinder must have the studs and tappets removed prior to shipping it to us or arrange with us prior to shipping to have us remove and replace the studs and tappets.

• When we receive your cylinder we will do a rudimentary clean up and measure the pistons and cylinder to make sure the correct size pistons are being used and that the cylinder is in good shape.
• If you elect for us to clean and paint your cylinder, we will bead blast and thoroughly clean up the cylinder.
• We then bore the cylinder to within .001" of the final skirt clearance.
• After the boring, we hone the cylinder to the correct skirt clearance and give each cylinder a good cross hatching to assist in seating in the new piston rings.
• If you elect for us to paint your cylinder, we will blank off the top and bottom of the cylinder and paint it.
• The last step is to surface the top of the cylinder using a special surface plate designed for this purpose.