You might need to try a smaller diameter wire like .023" or at the max a .030". I expect you are using all of the 90 amps just to melt .035" wire, making it difficult to create and maintain a decent puddle. Some of those instructions usually give some guidelines to use when choosing wire size for that machine and a rough setting to get you in the ballpark and you'll have to fine tune for your application from there. Basically they are set up with a couple voltage settings, and a wirefeed speed which determines the amperage by the rate of wire feed. Make sure the leads are hooked up correctly for DCEN for ESAB self shielded wire, check your wire recommendations. I looked up some parameters in a ESAB catalogue and for some of their self-shielded .035" wire it goes like this:
80amps/15v 81ipm w/ 3/8" ESO
120amps/17v 155ipm w/ 3/8"ESO
200amps/17v 392ipm w/3/8" ESO
Their .030" self-shielded:
40amps/15v 69ipm w/3/8" ESO
100amps/16v 175ipm w/3/8" ESO
160amps/16v 440ipm w/3/8" ESO
HTH,
John Wright