As noted here: https://github.com/BevoTechPack/BevoTechPack/issues/351

The gas generator can not be picked up if it contains fuel. Up on re-placing it, the fuel tank shows "Slurry: 0", instead of ether the previous fuel level or just resetting to empty. It is then unable to accept fuel, and the block can only be discarded and actually recreated/given to regain prior functionality.

With the update in BevoTechPack to V10, running:

Mekanism-1.7.10-7.1.0.92.jar
MekanismGenerators-1.7.10-7.1.0.92.jar

This issue persists.

I've now pushed the hopeful fix to master, could you try out build 7.1.1.96 to confirm?

\o/

Tested and confirmed fully fixed in BTP-10 stable, with Mekanism jars manually upgraded to build 7.1.1.96.

Behavior now is the generator does retain fuel inventory level when wrenched up then again placed in the world. Much appreciated!