I recently restored my Pop's old Genesis 3000. Up until this point I have only used a weber kettle, so this is my first gas grill. I still prefer the kettle for weekends and anything where I need indirect heat (like tri tip), but the convenience of the gas is pretty nice during the week. However, I've been having trouble getting a good sear on things, and it's very difficult to get any type of grill marks. Usually I preheat the grill until it's 450 degrees (about ten minutes) before I put anything on. It feels like the grill is quite hot, but produces very little sear. Should I be preheating longer, or is there something wrong with my grill? If so what do I need to fix? Thanks for the advice!