If memory serves, it's the cold start valve. It acts like a choke. And yes it would be very difficult to start. It's just a solenoid. Remove it, clean it with carb cleaner, small shot of WD40. Put 12V to it and you should hear it click and the piston (pintil) retract. If it does, reinstall it (check the gasket P/N
1171410780). A new valve is about $150.00 US. The cracked boot is not a problem. But, check the wire insulation.
Good luck, Dave