Hello All. New Member here. PLEASE HELP!! I have searched everywhere for a solution to my problem, hopefully someone out there will be able to help. Here is my issue. The ATV in question is a 2009 Honda TRX420 FPM, FUEL INJECTED with power steering, ONLY 3300 km. The bike starts easily every time, and idles like a champ. It even revs up to about 2000 to 2500 RPM (just guessing) perfectly, HOWEVER, when I try to rev it up any higher, it starts to act like it is being starved for fuel - sputters and runs rough. If I keep giving more gas, it will slowly develop slightly higher RPMs but still sputters. If I back off the throttle quickly, it will often backfire. I have a video for anyone that needs it. PLEASE NOTE, this is FUEL INJECTED and NO ERROR CODES are being displayed on the dash. ALSO, this is a new ATV to me so I do not know the history. I didn't notice any of these symptoms when I purchase the ATV (I have owned many in my 56 years, so I kinda know what to look for). I did, however, PRESSURE WASH the quad when I got it home. Not sure if this is what caused my issue. Here is my TROUBLESHOOTING THUS FAR: 1/ Replaced fuel filter, 2/ Checked valve lash (perfect), 3/ Replaced spark plug 4/ Drained fuel tank, removed petcock and inspected filter screen (it was clean), filled with fresh gas, 5/ Checked fuel pressure (it was 50 psi at idle, similar when attempting to rev). Checked voltage to pump (was 13.8 volts) 6/ Checked voltage at battery (14.2 volts when running), 7/ Inspected PGM FI unit connections. There was a lot of mud around the unit and other relays etc, and I saw evidence of muddy residue inside connections. Cleaned the PGM FI connections, as well as the other connections, with electrical contact cleaner. 8/ Removed muffler (no change) 9/ Replaced injector with new OEM part, 10/ Replaced coil with new aftermarket coil, 11/ Replaced TP/Map sensor with used part, 12/ Cleaned all connections from engine back and re connected using dielectric grease, 13/ Cleaned main ground to frame, 14/ Removed and cleaned throttle body, 15/ Removed and inspected IACV (moved freely), 16/ Replaced PGM FI unit with used part. PLEASE NOTE: Engine seems to rev properly when petcock is closed and just before it runs out of fuel. If petcock is just cracked open just a hair (restricting fuel flow to pump), bike will rev well until it runs out of fuel. To me it appears it is getting too much fuel, which is supported by the fact the plug is black after running for a while attempting to rev. I HAVE NOW RUN OUT OF OPTIONS, AND MONEY FOR PARTS THAT DON'T WORK!! Any help would be greatly appreciated, and thank you all in advance. Will