Need TiG Help With Old HeliArc 250

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Well I finally got a Tig welder it is an old Heliarc 250 given to me by a friend.  I have not done any Tig for about 25 years so I am not an expert by a long shot.  I wanted a Tig to weld motorcycle exhausts (mostly 20&22gauge) also I build motorcycle tanks from aluminum which I have been welding with gas.   So I fired the TiG up and it seems to work ok accept that on the low setting it won't arc up unless I give it full peddle then it will just burn a big hole.  I am working with 20gauge cold roll sheet and I am using the middle 35amp setting (just because the low 5 amp doesn't seem to be working) but I have to run it with the pedal almost off to keep the amps down and sometimes it just shuts off because I am backing off the pedal too much.  Anybody have any insight as to why I can't get it to run on the low range?  I assume that the 5amp position is the lowest and with the pedal it would go up to 35amp, is that correct?  I tried playing with the high freq dial and the current control but still no joy on the low range.  Also how far from the work should I be holding the tungsten?  I am using 1/16 red tungsten.I cleaned and adjusted the points on the high freq but it made no difference.  I think the Hi freq isn't working and that's why I can't get it to start on the low range but I could be talking rubbish as I don't know what it feels like when the high freq is not working!All suggestions appreciated! Attached Images
Reply:Here is a copy of a manual that should work:http://www.google.com/url?sa=t&rct=j...86956481,d.cWcThe 5 amp minimum is the one you want for thin metal (it goes up to 230 amps on that setting).Set your two switches to Tig and Remote.Turn your HF intensity all the way up.Turn your current control about half way and see if it works.Last edited by MinnesotaDave; 02-26-2015 at 02:24 PM.Dave J.Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~ Syncro 350Invertec v250-sThermal Arc 161 and 300MM210DialarcTried being normal once, didn't take....I think it was a Tuesday.
Reply:Here is the problem. The leads going up to the range switch are alum buss bars lugged with wire mesh interfaces that get loose over time. Looks like you have to smash the pedal in order to arc between the stainless mesh. If you persist they will overheat and the heat will flow into the switch and soften the springs between the contact plates. I had a Heliarc300 in which I had to rebuild the switch and build new bus bars from silverbrazed copper. Worked well for about another 10 years before I killed it off completely.Pull the cover off and check those leads to the switch.Weld like a "WELDOR", not a wel-"DERR" MillerDynasty700DX,Dynasty350DX4ea,Dynasty200DX,Li  ncolnSW200-2ea.,MillerMatic350P,MillerMatic200w/spoolgun,MKCobraMig260,Lincoln SP-170T,PlasmaCam/Hypertherm1250,HFProTig2ea,MigMax1ea.