SA-200 not welding???

[elcincocinco]

Hey guys, I have a 1960 sa-200 blue dial machine with a 4 cylinder Kubota Diesel engine (really sweet!). It’s not welding right now just small sparks and the grinder runs but very slow. It does idle up when I try to strike an arc or when I hit the grinder trigger but not full power. I was actually grinding with it when it all happened. I checked the main brushes, exciter brushes, checked the pc board, I looked at the rheostat cables and they looked fine. I think it’s the exciter coils. What do you guys think? Thanks a ton!

[ronsii]

I think you're going to have to take some voltage measurements to get abetter handle on what's happening and then some ohm readings for the coils and brushes... I'm sure some of the guys that know these machines inside and out will be around soon to let you know where and what to test

[12V71]

Hey guys, I have a 1960 sa-200 blue dial machine with a 4 cylinder Kubota Diesel engine (really sweet!). It’s not welding right now just small sparks and the grinder runs but very slow. It does idle up when I try to strike an arc or when I hit the grinder trigger but not full power. I was actually grinding with it when it all happened. I checked the main brushes, exciter brushes, checked the pc board, I looked at the rheostat cables and they looked fine. I think it’s the exciter coils. What do you guys think? Thanks a ton!

If you were grinding when it happened, you may have opened up a connection in the exciter circuit.

[elcincocinco]

Checked the coils with a meter and it read OL so I guess it is the coils

[charlie53843]

You can fixed coil if need to? Take coil out the 4 four bolts on side exciter housing , it easier if take exciter rotor out first unhook wires and brushes holder ,,once get coil out you can test find what coil is bad the total ohms of both coils are supposed 167 +- 10 ohms ,, so one coil is half of that is 83.5 with coils on bench small strand wires that joins two together in middle, cut little slit to exposed wires so can get ohms meter probe stick in ,take the other probe hold on other eyelet small strand one coil at time one read 83.5 the other read open line which be bad coil ,, take glass tape wrapper off that coil ,, what happen is moister seep down to bottom corners and rusted wire broken ,, the green oxide wires will be dead giveaway to were it be broken ,,, you get tweezer and pick wire away to get to it and buy sames dia roll wire ,(bought mine at Radio shack many years ago) twist new short piece wire to connect both side solder them up and retest,, see if get 83.5 or eyelet tow eyelet on both coil see get your 167 ohms,, once you got coil fixed spray electric varnish in all four corner too prevent from happen again ,also take other coil wrapper off and do same spray varnish on good coil ,, then rewrapped both coils,,,

[kolot]

May want to check the connection between the two coils, sometimes it breaks and you get the open reading, simple fix if that is it. take cover off the end and look for the wires, often bolted together if the machine had been serviced in the past.