[Roadsters] 44PHH2 Type Q fuel leak

[RWM]

 From out of the blue I am experiencing fuel system issues.  Car had not 
been run since last Fall, first wouldn't start (lack of fuel, traced as 
noted below), ran well for a couple of laps around town, then picked up 
a stumble and a carb/fuel leak from one of the old style 44PHH2 Type Q 
Mikunis.

Remaining issue is a cylinder out/slow throttle response while running, 
accompanied by a significant raw fuel leak out of the #4 (rear-most 
rear) carb throat after shutdown and most likely the cause of the 
cylinder-out while running condition.  Stuck float valve or sunk float, 
perhaps?  (For insurance, I run one in-line filter before the fuel pump, 
two in-line filters after the pump, plus the banjo fitting mesh screen, 
so I wonder what it could be that got by all that filtration.)

Also, is anyone seeing the "new gas" (high alcohol content) causing 
rapid deterioration in fuel system gaskets?   Had to rebuild the fuel 
pump due to a piece of debris (looked like solid varnish) stuck in a 
body valve.  In the process, went from no fuel delivery to the fuel leak 
noted above.

TIA for suggestions/recommendations.

- Bob Mann, '68 2000 Solex