All three of mine that are setup like that get that much run time on them per tank, all are setup the same with the same needle settings etc. One of them has over 70 gallons of fuel on it still running on original parts (and makes better power than the other two!). That cant be a coincidence that all three are essentially identical.

Running bigger props without the restrictor 11-12 minutes was all I was getting, but I find the motor just runs much better with the restrictor on smaller props.