High RPM Backfire when fully warmed

All the info on the Hughes spring.

https://www.hughesengines.com/Index...bnVt&level1=VmFsdmUgU3ByaW5ncw==&partid=35162

Personally I’d throw jet in it first just rule that out. The temperature variation still has me worried. Why would it float the valves hot but not do it when cold? Seems like if the spring looses control of the valve it’ll do it at any temperature.
Imma do that as well before!