Reg,
No direct replacement. Standard o-rings have equal width and annular gap. So while a -116 o-ring would be 3/4 i.d. and 15/16 o.d. (0.728 i.d., 0.943 o.d. and 0.103 width actual), the width would be only 3/32 inch. Step up to a 1/8 inch section o-ring (-210; 0.139 width actual) and the section is too big to fit the existing o.d. You can get the same o-ring in round, double seal (x-cross section) and multi-seal (eight point start section), but they all follow the same shaft/bore/width conventions.
The -116 o-ring would stretch a little on the 3/4 inch shaft and probably take up slight gap at the o.d., but it is still a little narrow in the existing groove. It might work though, and cannot be any worse than a worn felt! Problem is it is a lot of bother to strip the case down to that point, so you only want to do it once.
-Doug
-Doug
