Operability issues such as flashback and lean blow out are phenomena that must be addressed for successful commercial operation of stationary gas turbines. The present work focuses on flashback and lean blow out of premixed jet flames in a combustor from a commercially available gas turbine operating on synthesis gas compositions. The issue of flashback is exacerbated when operating on fuels with high hydrogen content due to the increased reactivity of hydrogen, thus increasing the propensity for flashback. Operating margins for mixtures of natural gas and carbon monoxide in hydrogen are reported. The results interestingly demonstrate reduced stability for mixtures of H2/NG than for H2/CO. Increasing H2 percentage from 0% to 100% reduced blowout equivalence ratios from Φ = 0.63 to Φ = 0.29 for H2/NG and Φ = 0.42 to Φ = 0.29 for H2/CO. In addition, results obtained for inlet temperatures of 300K and 623K are compared and show an upward shift of the stability limits for higher preheats. Modeling of the experimental data using a perfectly stirred reactor predicts the effect of the addition of H2 to natural gas on the blowout limits. With regards to flashback some key factors that dominate the characteristics are identified and attempts to correlate data are carried out. The results show that lean blowout and flashback occur at the same AFT, regardless of preheat temperatures. AFT at flashback and lean blowout are compared to a more fundamental burner [1] with results indicating reasonable scalability.