John Deere L110 crack backfire no start

[DezWalnuts]

A few months ago I started trying to replace the head gasket on my John Deere l110 kohler 17.5hp cv491s since shop was going to charge $1000 for it to be replaced. After replacing it ran fine but leaked oil from valve cover. I removed sealant I used and cut out a gasket out of material. After reassembly the engine shot flames out intake, had no exhaust coming out of the muffler or header, and leaked gas from fuel solenoid so I replaced it, it stopped leaking but still did the same thing there isn’t any ticking from the rockers as far as I’m aware, there is also no way to check the spacing on the them because they have a washer on them that automatically spaces them. The fuel pump does leak but it has leaked for many years and hasn’t ever created a problem, I don’t believe it’s a timing issue since I never messed with the timing or flywheel. I checked the timing and it’s on time and the flywheel key is intact. I haven’t messed with the carb adjustments since it ran fine before I replaced the head gasket. I just don’t know what could be causing this issue. Please I need help!