Monty and or Neil, feel free to chime in

I briefly posted something like two weeks ago about this but did not detail the situation.
I have a Bonito in a TLR 8-T 9901 41021 Byrons 30/9. I do not count fuel but prob has 3.5 Gallons or so (new this year)
Recently when the Tank opens and it is refueled (or not fueled, just the tank even opens) it pulls off with a CHOKING sound and maybe a little rattle (hard to explain) and sometimes it will catch itself back up and continue running well and sometime it will FLAME
ALSO not sure if they are the same situation, but to get it to clean out and run well, it is HOT (i know they like to be warm) but we are around 300 F
ANY ADVISE????

I have only broken the engine down ONCE (I am new to RC this year, and although mechanically inclined, I am a little worried I will mess something up pulling it apart) the one time I did pull it apart was months ago, and it ran great for the longest time, now I just have this issue