You may have been expecting a normal sized kernel but if you don't disable these .config options you may have a kernel that is several gigabytes.
CONFIG_SLUB_DEBUG=no
CONFIG_DEBUG_INFO=no
CONFIG_DEBUG_MISC=no
Rebuild and you should find that the kernel is the normal and as expected size.
linux, custom, kernel, solutionyou, sized, disable, config, gigabytes, config_slub_debug, config_debug_info, config_debug_misc, rebuild,