20+ year old Mitsubishi MEK 5800 generator needs help

Hi all,
Trying to get the above captioned generator back in service. I have had it running, but the carburetor needs work.....gummed up with ethanol!! In trying to remove the main jet I destroyed the brass at the screw slot, and had to use an extractor to remove it. Also, I broke off one of the fuel supply nipples. As this is pressed in, I'm thinking of trying the extractor again, or heating in the oven at about 350 to see if the aluminum body will expand enough to let me get the piece out.
In any event, I have tried for a few days to identify both carb and jet on line with no luck....the only numbers on the jet are "A27"....it is a Mikuni carb.
Any helpful advice appreciated,
Thanks