RE: carb diaphram replacement color/material
Well, this will probably get me in trouble too, but I am not against ethanol, and I think we should basically switch to it as Brazil has proved feasible. That would break the stranglehold the oil companies and the Arabs have on us and our economy. It would be a bit troublesome to switch, having to go to all alcohol compatible components in our fuel systems, but the payoff could be great. Everything you can think of somehow depends on petroleum. If we could switch to (hopefully) cheaper ethanol, it would benefit our economy greatly. The crops would put closed down farms back into use, use otherwise vacant land, generate oxygen and soak up "greenhouse gases". But that is just my opinion...
What I use for a storage fuel is Coleman fuel mixed at 20 to 1 with oil, (Pennzoil in my case), and Sta-Bil gas stabilizer for good measure. It is probably overkill, but using it as an afterrun fuel, and then leaving it in the tank and carb, has solved the diaphram, fuel line, and carb in general problems we had been experiencing. I have 12 flying planes in my fleet, and some of them sit for long periods of time before being flown again. Using the storage fuel, I have had planes sit for a year, and work perfectly upon the next use. Note that I do not recommend flying with Coleman fuel due to its very low octane. (I know some people report flying with it and having no problems, but I still don't recommend it.)
I agree that ethanol may or may not be the culprit when experiencing carb problems. But whatever is in the fuel in the Tucson, Arizona area is hell on carbs. I often buy huge lots of yard equipment to fix and resell, and use some of the engines to convert for airplane use. 80+ percent of the problems the machines I buy have are gummed up carbs, bad diaphrams, and ruined fuel lines. Often times the fuel lines turn to a gummy "mush" that you can squeeze with your fingers and the fuel line disintegrates and sticks to itself and your fingers like glue, and the diaphrams in the carbs are either rock hard or severely distended.
AV8TOR