My Cummins P9500DF generator turns over with the electric starter but the engine will not catch and run. I'm forced to use the pull starter which works but is frustrating. I'm not the sharpest knife in the drawer mechanically but it appears that the battery that came with the unit is not powerful enough. If I add power with my jumper cables, the generator fires up immediately. I would add a larger battery but the battery space is very specific and won't accommodate a larger battery. I purchased a new battery but the problem exists. Cummins/Onan is a good name and it's hard to believe that they undersized the battery on this model. Appreciate your thoughts.