[dwarf66]

I need to open up a motorcycle flywheel slightly larger, but it has a tapered bore. I need to adapt it to a larger tapered crankshaft. How can this be done. I have an older 9" Logan lathe that runs well. What tooling would I need and the procedure? Thanks
Marc

[widgitmaster]

If the lathe has a compound tool post, put the shaft in the spindle and use a dial indicator to adjust the compound to the same angle.
Then put the flywheel in the spindle and use a small rigid boring tool to machine the taper until it fits the shaft.
Run it slow and take light cuts, as the taper will enlarge rapidly and you can overshoot the point of proper placement.

When doing one piece sets, take your time and go slow!
Eric

[Mcgyver]

to add to what Eric said, its critical that the indicator contact be dead on centre height, not easy to do unless you build/have a z axis to adjust it. Id eyeball it to centre height, cut the internal taper into a piece of scrap and fine adjust (tap) the compound around until it the scrap is a perfect mate with the crankshaft (using blue to check). then and only then cut the flywheel. hold the flywheel in a four jaw or face plate and get it perfectly concentric with the indicator before cutting.