The Complete Beginner’s Guide to Setting Up Your Jasic EM-250CT for Perfect MIG Welds

Whether you’ve just bought a Jasic EVO MIG 250CT or you’re looking to get the best possible weld quality from your machine, this guide will walk you through every stage of the setup process.

We’ll cover:

Machine setup
Polarity
Shielding gas selection
Wire installation
Feed roller selection
Synergic mode
Manual mode
Recommended settings for every steel thickness
Troubleshooting common problems

What You’ll Need

Jasic EVO MIG 250CT
ER70S-6 MIG wire
Argon/CO₂ shielding gas
Regulator
Earth clamp
Correct drive rollers
Contact tip matching the wire diameter

Step 1 – Install the Wire

For general fabrication use:

0.8 mm ER70S-6

This covers approximately:

1 mm
2 mm
3 mm
5 mm
6 mm mild steel

Install the reel so it feeds from the bottom into the drive rolls.

Step 2 – Fit the Correct Feed Rollers

Use the roller groove that matches the wire:

0.6 mm
0.8 mm
1.0 mm
1.2 mm

Too much roller tension can flatten the wire, while too little causes slipping.

Step 3 – Connect the Shielding Gas

For mild steel:

90% Argon / 10% CO₂ (or 92/8) is an excellent all-round choice.

Set the gas flow to:

10–14 L/min indoors

Increase slightly if working in draughty conditions.

Step 4 – Check Polarity

For solid wire:

Torch = Positive (DCEP)
Earth = Negative

For self-shielded flux-cored wire:

Torch = Negative (DCEN)
Earth = Positive

Step 5 – Turn On Synergic Mode

The EM-250CT’s synergic mode is one of its biggest strengths.

Select:

Material: Steel
Gas: Ar/CO₂ mix (for example, Steel Ar80%/CO₂20% in the machine’s program list)
Wire size: 0.8 mm
Torch: Standard push torch

The machine will automatically calculate the wire feed speed and voltage based on your selections.

To activate the synergic mode press the black button on the left hand side of the screen with the marking “SYN”

If you then press in the top black knob on the right hand side 3 times you will see an icon illuminate showing an 2 arrows pointing to a line this is indicating material thickness.

You can now select by scrolling the know right or left your desired material thickness and the machine is then fully set for the thickness and you are ready to weld.

These are excellent starting points. In synergic mode, the machine will automatically coordinate the voltage and wire feed speed, and you can fine-tune the arc length if needed.

Fine-Tuning the Arc

If the weld feels:

Too Harsh

Increase the arc length slightly.

Too Soft

Reduce the arc length slightly.

Small adjustments usually produce noticeable improvements without changing the overall synergic program.

Pulse MIG Setup

The EM-250CT also includes pulse welding.

Use Pulse MIG for:

Aluminium
Stainless steel
Thin sheet
Cosmetic welds

Benefits:

Less heat input
Reduced distortion
Almost zero spatter
Excellent bead appearance

Common Mistakes

❌ Wrong drive roller

❌ Incorrect polarity

❌ Gas flow too high

❌ Worn contact tip

❌ Dirty steel

❌ Stick-out over 20 mm

❌ Poor earth connection

My Favourite Everyday Setup

If I were setting up a customer’s EM-250CT for general workshop fabrication, I’d choose:

0.8 mm ER70S-6 wire
90/10 Argon/CO₂
Synergic mode
Steel program
0.8 mm wire selected
12 L/min gas flow
Arc trim at 0
Stick-out around 10–12 mm

Jasic EVO MIG 250CT Setup Guide