I thought my suddenly over-rich running 235 was due to another ethanol inflicted accelerator pump diaphragm in my YF2100.
So I proceeded to remove the gas line from the carburetor, when a seemingly never ending flow of gas gushed out of the gas line. I quickly tightened up the gas line and took off the gas cap and a huge rush of air spewed out. I am assuming that the non-vented gas cap allowed pressure to build up, forcing gas to be pushed past the rubber tipped float needle, causing excess gas to go over the top of the bowl and into the intake. I drilled a 1/8" hole in the cap from the bottom and solved the problem.
