You are absolutely not the candidate for a Lithium LifePO4 battery. You leave the key "on" dead battery. Once drained to less than 6v, trash.
I'm wondering if you have too much oil in the engine. When you are trying to start it, the excess is being forced out somewhere. If it's the fill cap, the O-ring may have shrank a little during non use. Another 20 cent item. Replace it.
06 Paul Smart Sport Classic NFS ever.
08 S4RS Tricolore #081 NFS ever.
01 M600, aka, The Pink Monster
97 900SS CR
72 Norton Commando 750
03 KX60 with S4R rear shock,Honda CB350F, Hodaka Ace90, 3x Yam-YGS1, Yam-CS3 200, Vespa small frame, Gilera 106, Puch Sabre, Puch 50 Boy Racer, Ducati 250 bevel, Benelli 250, Benelli 360, Honda CB350T, and many more.