Hobart 140 with flux core wire and the welds are breaking

Hi:
Sounds like you have the wrong polarity in your machine. If you are using flux core wire, make sure to connect your ground clamp to the positive side and your gun to the negative side. Dial the right voltage and wire speed according to wire size and metal thickness.Let me know if this help.
Regards,D.S.

If you are using solid wire, you need to use a shielding gas like Carbon Dioxide or Argon. Otherwise you will not get *********** and the wire will leave random blobs.

If you are using flux cored wire, you do not need the shield gas as the core is producing the gas shield.

This should remedy it.

I have found that keeping the gun lead as straight as possible fixes this problem. Also it is sometimes recommended to use one tip size bigger when welding with flux core wire. My last spool was radnor flux core wire .030, and a .035 tip keeping the lead as straight as possible and it welded extremely well. If that doesn't solve it you should take everything apart and clean it / blow it out with compressed air.

snip wire loose from spool -- hold trigger down and pull excess wire out of trigger

First there is a overload for the drive motor incase the welding wire gets jammed. I've had one of these for a number of years and only recently understood the markings on the drive wheels. When the wheel is installed, the markings for the wire size is for the wire you're using. In other words, the marking is towards you but is indicating the size for the rear groove. For years, I looked at the numbers and assumed that they were for the groove closest to the numbers. I had no problem with solid wire, but with flux core all kinds of trouble. So, make sure you have the right groove for the wire size. Second make sure there are no kinks in your hose. Make sure your contact tips in the gun are the right size for your wire and in good condition A person has e a tendacy to make ther drive wheels tighter when the feed slips, this can cause problems for the flux core wire if the correct drive wheel is not selected.

Check your input line voltage. 115 volt Mig welders / plasma cutters need stable voltage / current. Test to see if the voltage drops to below 100 volts when welding. If so, find a more stable power supply.

check bridge rectifier ,sounds like it went bad.

If it is new i would not play around with the welder Just take it back to where you bought it get them to replace it under warranty

check diode bank,sounds like a diode or two are bad.

make sure rollers are clean and slots not wore out check alignment
do not over tighten wire feed so it smashes the wire
flux wire is hard to get a good setting
make sure if you can set it for gas welding it is not on this setting