Wire not feeding right

[Oldgrandad]

I have a Millermatic 250 serial #KC253855. Started having feed problems. Welding along and the wire stops feeding. The rollers are doing their thing but the wire just wont feed consistently. Change out the rollers, liner, contact tip. No change Take it to a weld repair guy I trusted cause I just couldn't figure it out. Short story with him, he changed out everything I did and couldn't get it to work and charged me more than what I thought was fair. Don't trust him anymore. Got it back tried a whole new gun, well machine still doesn't work right. Thought maybe drive motor. Look it up on Miller web site, discontinued but they had a replacement number. Ordered it around $300.00. Motor showed up yesterday NOT EVEN CLOSE. Shaft is wrong size and original has 4 mounting screws new one has 3. Anyone out there have any suggestions. I'm lost.

[G-ManBart]

How is the wire feed with no load (wire)? Can you just hold the trigger and the motor will run for minutes on end smoothly? Have you checked the internal connections and wiring? Loose or degraded work clamps and cables can cause oddball symptoms as well.

[blue_tech]

Am I understanding the issue correctly? You start welding fine, but then the motor is still spinning, the drive rolls are still spinning, but the wire is not feeding out the gun? Or is the motor stopping after you weld for a bit?

[Oldgrandad]

The motor doesn't stop. The wire isn't coming out of the gun consistently. It acts like it's there is a kink in the liner but the liner is new. The motor runs fine with no wire, haven't run it to long like that but starts when you pull the trigger and spins fine. Changed that short piece of ground cable in the machine. Pull the trigger and try to hold the wire between the spool and the rollers, can't stop it, the rollers pull hard. Out of the gun, run the wire into my hand with my hand about 3" away from the tip and the wire spools up a bit but starts to bind up and the rollers do a burn out on the wire. The other 4 mig welders I have don't start have trouble feeding until my hand is about 1-1/2" from the tip. I'm going to swap out the liner again, This just doesn't make sense to me.

[G-ManBart]

It won't hurt to check the roller alignment carefully and then set the tension on the rollers the way the manual recommends. The tension spring on the wire feed can weaken over time and need to be replaced. If it's too soft it won't put the proper amount of tension on the top roller.

[ASKANDY]

Release the drove roll tension lever.
Pull the wire through the gun manually from the tip. If you encounter resistance you may have a bad roll of wire.
Check the wire roll to make sure the wire is spooling off the TOP row. A lot of times these spools are wound wrong and the wire will start "underspooling" which will work for a few seconds and then get hung up.
The other thing to check would be the spool tension.
Cut or spool back the wire onto the spool. Turn the spool by hand in the direction of wire pull. If there is resistance, then the spool tension spring could be too tight or the slip washer behind the spool hub is worn.

[aametalmaster]

Hi Andy long time no read…Bob

[ASKANDY]

LOL
I troll here once in awhile!:-)
Been covered up doing content development but still love the forum!

[Oldgrandad]

Thanks G-Man I'll check roller alignment. I've done the tension spring thing from not enough to too much and back to where I think it should be. Andy thanks the spool is wound good, the tension spring on the spool is the last thing I took apart it is spinning smooth. Next I'll put another new liner in, maybe I have a brand new bad liner in it. If that doesn't do it I'm going to let this wonderful machine sit for a day or 2 and think about continuing to give me a hard time. I'm ready to take it out shooting or maybe fishing .

[ryanjones2150]

Do you have another lead you can try on it?

[justBill]

From what you have checked and told us about it has to be a liner or restriction in the lead the liner is in. Any chance you have dropped something heavy on it? Take the tip out of the gun and does it feed then? I have had tips that clogged with junk or spatter that restricted wire. watching this for results!

[Oldgrandad]

new tip... The only restriction I feel when feeding the wire by hand is when the wire gets to the neck on the handle kinda hard to push it passed the neck. Once the wire gets passed the neck if moves easy. I haven't tried welding with the gun for a bit using another machine I'm so fed up with the darn think don't want to loss my $hit if it continues to not work. I'll get back to it in a few days.