Hello there, I have a coleman powermate PM0606750 / Powermate pro 6750 yamaha engine, I was using it for a 110v stick welder, then suddenly the welder stops, its look like it trips, I look at the receptacle where its plug keeps pressing reset but it won't work, I remove it and plug it to the 2nd 110v receptacle and it works, but then I unplugged it and turn off the generator, thought I rather use the 120/220v with 30 amp, when I turned off the generator I smell something really stink, not a burn rubber but it stings in my eyes, then I tried to start the generator it won't start anymore. Checked oil and fuel was OK, please I need help I really love this generator...

Hi,
It is not something you will want to hear; but the smell and the fact that it burned your eyes sounds as if it is the insulation on the stator or rotor or both. The fact that one plug failed would seem to say you were running it very near to capacity. In a case like that it is wise to allow the machine to run awhile without a load to let the fan cool it down. Otherwise the heat is just trapped where it can do damage.
I have a link to the parts breakdown and B51B and B51C are the parts I refer to at:
Powermate PM0606750 Parts List and Diagram : eReplacementParts.com
Peace,
Clarke