This thread is of special interest to me. I joined this list initially as I was, still am, in the process of rebuilding an obsolete jet ski engine. It has been pushed aside many times due to other, more pressing issues, but I am always on the look out for ideas to help me complete the project. As you mention Tony, there is no one around here that wants to mess with boring this engine. So I am going do it myself. I have thought about and discussed here on a couple of threads about just honing it to size. But I think I am going to have to re-sleeve the cylinder, so the honing is not really a very good idea. The engine is a 2 cylinder 2 cycle. Both cylinders are in the same jug, so spinning the jug on my lathe is not possible. Bore and stroke are 83 mm x 71mm.

I am wondering if my lathe is up to the task of doing this in similar fashion? I have an 11" Powermatic/Logan. I am wondering about the stiffness of my spindle. The spindle is smaller than most 11" lathes. The through hole is just large enough to get 1" round stock through it if there are no chips in it. The taper is some proprietary thing in the range of #4 morse, but the taper does not match and it is about 1/2 the length of a standard Morse taper. The spindle nose is 1 1/2 x 8 thread. I am sure the internal taper not up to the task.

I am wondering, assuming that I have the skills to actually make the adapter, do you think the spindle is stout enough to attempt to make a similar boring set up using the external threaded part of the spindle nose? Possible I can make the set up stiffer, using the tail stock as Toolmaker mentioned?

Thanks for your input.

John