ISSUE RESOLVED. 3 overnight soaks in 2-cycle oil; I had also opened up the gov. housing and was lucky to be able to put it back together but it could have cost me a rebuild! Gum and varnish are still in there so I'll use Lucas diesel-treatment in purge mode for a while and then in just preventive mode. I have no explanation for this, 300 hours after a rebuild instead of 9,000! I keep my fuel very clean.