Onan 4K Microquite KY series generator runs, stops, over speeds etc.

[WHallTN]

For all the Onan gurues out there here's another mysterious quirk.

Generator sat idle for a year or so-wouldn't start. Drained main tank, purged lines with fresh fuel, got it to start but died. Removed carb, cleaned-ran rough, but ran, cleaned carb again. Replaced fuel filer and pump. seemed to run Ok for 5-30 minutes at a time then died. Wouldn't restart without manually manipulating choke-black smoke coming out of exhaust. Had to wait until it cooled completely before it started again. Ambient temp in the 50's. Again, would run for 5-20 minutes and then started to overspeed and shut down (code 14-overspeed condition sensed).

Backed off governor. Ran fine, put microwave and AC load on-ran great. Ran again later, microwave and AC load and when microwave timed out unit oversped again. Wouldn't restart until after cooling.

Ran it yesterday (temps below freezing) ran for 40 minutes until I shut it down.

I've read a ton of posts about this generator and am left with three things. First, fuel enrichment jet still not cleaned (although will sometimes run perfect for among period of time wth load/no load. Secondly, bad control panel affecting voltage regulator (although I get 125 volts consistently. Third, carberator itself is jacked up.

Troubleshooting:

-oil level checked and good
- fresh 100% gas with fuel treatment added
-voltage checked at AC outlet good-125 volts
-carb cleaned-three times
-fuel selonoind cleaned and works
-all wires checked for clean connection and grounded
-hooked up an external fuel cell to bypass entire fuel supply

While my intention is to run an external generator set (Honda EU1000 and EU 2000 parralled to provide longer running AC requirements) I'd still like the internal genset to work.

Only thing I can see changing is a new carb and/or control board. But that's not cheap.

Thoughts??