Miller trailblazer 251 onan performer 20 problems

[Bamb7169]

Just purchased this machine seems to be a nightmare. Anyway here we go for one it wont weld in ac mode and two when i swith from the #14 swith to get power to my welding leads it stumbles and starts to flood
switch it back topower the #14plug and it runs awsome any idea what my problems are??

[D Auger]

Need the serial # of your machine also if you go to miller welds you can download a manual for it .That may help you trouble shoot it faster . D

[Bamb7169]

Serial# kh334119

[Aeronca41]

It may be that the engine will run fine with no load but won't deliver power. Have you tried powering a relatively heavy load like a couple of electric heaters on the 120 or 240 volt outlets? Will the engine deliver power or does it bog down? Leave the weld output switch in the "remote" position with no remote connected for this test. How do you know it's flooding rather than starving for fuel when you try to weld? Black smoke?

[D Auger]

Does the Dc side weld with no problems ?

[Bamb7169]

Dc welds fine but with the engine running so poorly i think it affects the arc but in ac all i get is a very small arc not enough to keep the rod lit

[Bamb7169]

Hooked up a heater and a toaster oven no change runs like a dream in the remote position with nothing plugged into the remote .as soon as i switch out of the remote it spits and sputters with an accasional pop through exaust when i throw the switch from remote to to machine side.lots of raw gas smell when this happens

[Aeronca41]

Sounds like you may have a couple of problems. There are far fewer parts in use inside the machine for AC welding than for DC. I'd look first at the polarity switch and associated wiring for bad contacts or connections in the AC circuit.

I have that same engine on my TB 280NT but have never had to work on it. I assume it has a carb float like most small engines. A problem there would allow flooding; really need someone with Onan experience to weigh in. I also know these engines are prone to carbon buildup, but don't see how that would result in flooding--more likely lost power.

[D Auger]

Make sure you have fresh gas supply ,good plugs and clean carb and air filter like aeronca said sounds like couple things ,check to see if you have 12volts at coil pos at idle no load then at high idle weld power speed no load you have to get the engine running well first for proper rpm at idle for generator power and at weld speed first.Sounds like as soon as you put a load on it with the remote on it is taking power from your ignition circuit causing a Rich burning condition .I will check the manual for it tonight maybe someone can post it i was having trouble posting it.D

[D Auger]

https://www.millerwelds.com/support/manuals-and-parts

[H80N]

Engine Manual

http://www.mytractorforum.com/images/reference/Onan_16_18_20_24.pdf

[D Auger]

After you get it running well with the engine manual that h80n posted ,and make sure all your connections are clean and corrosion free behind the panels ,check the trouble shoot table in the manual .

[Portable Welder]

Based on what your saying, it sounds like your having a dead short, if the dead short was on a small wire you would quickly burn the wire in 2, but this dead short could be on a big line, Try running some big rod turned all the way up.

[Can You Weld This For Me?]

Hard to say without being there to see / hear what's going on. I'd suspect dirty carburetor, rotten / collapsed fuel line for the stumble. For the no AC weld I'd suspect corroded contacts / switch.

[D Auger]

Did you get this one running better ?