Doesn’t rev past 6000rpm, dies when riding

[grm24_imp]

Took a look at the battery yesterday and it didn’t have a date on it, but it does look like the original battery. Looked at the cables and they seem fine. Going to try swapping in a new battery from another bike and seeing if that does it. I’ve ran sea foam through it once but plan on doing it another time. Will also try ethanol free gas.

It currently has a delkevic slip on, would that cause issues? I assume it would lean it out but not sure how the fuel map on these work to compensate for it.