My 2008 ,750 Brute force, fuel injected is acting up.

was running poorly for the past week. at about 1/4 throttle she runs fine, idles fine. when i try to open her up or increase throttle she bogs, hitches, backfires and will not clear herself.

i was thinking poor gas which i changed, changed the plugs also....still happening.
Ideas Anyone?

 

I bet your fuel pump is not pumping out enough fuel at more than 1/4 throttle, causing fuel starvation. The pump has 2 filters, one at the bottom (inlet) and the other inside the fuel pump housing (outlet). There is no official replacement filters for this fuel pump which is quite expensive.