- Nov 14, 2009
How much material can I remove from the lower edges of the lifter tunnels (located on the cylinders) with out effecting anything? (1970 750 Commando) The reason I ask is that I have some rough edges on my cylinders in this area where it looks like it has fragmented away. I can also see some hairline cracks that i would like to remove now before putting the motor back together. Better now than it breaking away while its running and a smoother edge just seems like good practice. It is my understanding that this area must be relieved in order to run radical cam shafts. I just want to get some more info on this subject before I start removing any material.