Having issues with the mxu 450i series. The unit has sat for about a year after having issues with it stalling. We are currently trying to diagnose the issue. We recently replaced the battery as attempting to start it we realized the original battery was not holding a charge. We have put new fuel in the tank, verified that the fuel pump is initializing and pumping, the fuel injector is spraying, and we have verified spark and compression. The spark plug is a little dark, but don't know if it is actually fouled.
When attempting to start it, it turns over but never truly starts, just cranks. Any suggestions?