Interesting observation: Pump fuel vs. Aircraft fuel

53a1 · Post by **53a1** » Thu Oct 18, 2012 4:17 pm

Ran some regular pump fuel through the F134 engine in my test stand. Running a glass bowl fuel pump I notice the fuel evaporated from the bowl in a couple days even with the fuel line blocked.

Ran the same engine with 100LL and fuel is still in the bowl after two months!

I know Wes has mentioned evaporation in his fuel discussion but thought this was interesting anyway. Pretty sad if your fuel system is not sealed up considering the cost of gas these days.

Cacti_Ken · Post by **Cacti_Ken** » Thu Oct 18, 2012 9:08 pm

Maybe I should put a valve in the vent to close it off when I'm not using the jeep. But then I might forget to open it back up. I would have to put a red flag on the ignition swich to remind me.

Post by **wesk** » Thu Oct 18, 2012 9:28 pm

A trick to help you not start up when some device is deactivating a system is to make the handle on the device interfere with the closing of the hood or door near it.

But not venting your fuel system is not a good choice because as the tank warms up in the spring you will have an expansion issue that could be very damaging. The best choice is one of two choices.

Fill her with aircraft 100LL and run her 20 minutes or so before you store the jeep or drain all the auto gas from the entire system and inject a preservative into the carb for the winter.