bugfart said:
Not to derail the thread, but while on the topic of rings; I have some 58mm and I'm wondering how much you can trim off without causing any grief? I believe these are for a Homie XP2000 and 2100. Could these be filed down for reliable use on a 1050 (55.5mm)?
Well I wish it was that simple.It may work but they wouldn't seal properly,until broken in which would take a long,long time.
If you do a "google" search on making piston rings,there are several sites that explains the process in detail .The design of piston rings for 2 cycle engines is slightly different from 4 cycle.The expansive forces are much less,for example.This plus the fact that because of ports etc,the 2 cycle rings are pinned makes them a whole different item to deal with.
Geometricaly speaking,you are trying to squeeze a big circle into a smaller circle.In the process of making rings,they are cut to the exact diameter of the cylinder then split and expanded on a mandrel,using heat to anneal,then retemper the metal.
What you could do is make a lapping cylinder and lap the rings to size.This however would entail much more work than just getting the correct sized rings.Give ole Bobs lawnmower repair,in Maryland New York a ring a ding,I'm about sure he would have the right ones.