I have a 76 sa 200 that doesn't weld like it should.  The longer I weld the more I have to crank up the heat!  During the winter months it will weld pretty fair, but the summertime heat seems to have a big effect on the current.  I'm wondering, can the exiter armature be bad and still be able to weld?  Or, canthe main generator  just be breakin down from years of heavy use?  I've checked all the connections that I can reach,changed rehostat,cleaned both commutators,checked rpm's, and all brushes, even though they are original, seem to be fine.  When in the 120- 190 range +30 with a 1/8 5p+ I can be welding with a short arc and it will break arc about 4 times per rod. Overhead welding with this machine is difficult, erratic arc with lots af arc force but I can't seem to deposit much metal to the pipe, most of it ends up on me! Anybody have any sugestions on what I can do? I have an 03 200G but I sure miss my old 76er!