Going through the exact same thing on my sons 08. Bought the quad a couple months ago supposed to be bored to a 47?, has cherry bomb, Dasa exhaust, not sure about cams but were supposed to be new, basically "rebulit motor". Ran fine, pulled strong especilly with my 300#+ ass on it. After 1st good ride we found an oil leak on Stator cover. previous mechanic had welded i assume a crack on the cover so we have replaced it. Then discovered previous owner hacked on wiring harness some. Have repaired (soldered&heat shrink) several wire splices where they just scratched insulation back and wrapped wire around bare spot (smdh). They bypassed clutch position switch by wrapping tape around plunger on switch and stuffing under plastics (smdh). Discovered it had 7 of the 14 teeth called for on the front sprocket (lol replaced chain and sprockets). Cotter pin on rear axle nut was way too small and just barely stuck thru the nut (SMDH). Really just a piss poor attempt at tryin to be a mechanic.
So it started running crappy after a bath (we do tip it up on its tail so maybe we sloshed up some trash in tank?). Since machine is older and we have no idea what all has been maintained we basically have started from scratch. Pulled all Plastics and going over everything. Swirl filter was already deleted with an inline filter replacement. Inline filter was dirty (on the outside) so we changed it out. We checked fuel pressure at Fuel Pressure Regulator and had 42 psi but it dropped pretty quick after key off. So we rebuilt/replaced guts in the FPR (Fuel Pressure Reg.) and discovered they don't sell the o-ring for the FPR cover but measured it (30mm id x 35mm od x 1.5mm thick) and got a 6pk from amazon for $5. Removed, inspected, cleaned, and blew out all fuel lines and tank. Removed and disassembled fuel pump and blew carb cleaner and compressed air thru screen. We are replacing the o-rings on fuel rail/pipe at the injector. Replacing mounting screws at the injector because previous owner/mechanic was a buffoon with a phillips screwdriver. Think we've narrowed it down to a dirty injector so we're replacing with non OEM. Yes non OEM because OEM is +/-$200. Non OEM +/-$30. If the new injector works we will buy a better aftermarket as replacement/spare.
Any input as to what else we should inspect and or test? If injector isn't it we'll have to start testing sensors. but it sure seems like a fuel delivery issue.
GLOWING exhaust is typically a Lean Fuel mixture sign.
So it started running crappy after a bath (we do tip it up on its tail so maybe we sloshed up some trash in tank?). Since machine is older and we have no idea what all has been maintained we basically have started from scratch. Pulled all Plastics and going over everything. Swirl filter was already deleted with an inline filter replacement. Inline filter was dirty (on the outside) so we changed it out. We checked fuel pressure at Fuel Pressure Regulator and had 42 psi but it dropped pretty quick after key off. So we rebuilt/replaced guts in the FPR (Fuel Pressure Reg.) and discovered they don't sell the o-ring for the FPR cover but measured it (30mm id x 35mm od x 1.5mm thick) and got a 6pk from amazon for $5. Removed, inspected, cleaned, and blew out all fuel lines and tank. Removed and disassembled fuel pump and blew carb cleaner and compressed air thru screen. We are replacing the o-rings on fuel rail/pipe at the injector. Replacing mounting screws at the injector because previous owner/mechanic was a buffoon with a phillips screwdriver. Think we've narrowed it down to a dirty injector so we're replacing with non OEM. Yes non OEM because OEM is +/-$200. Non OEM +/-$30. If the new injector works we will buy a better aftermarket as replacement/spare.
Any input as to what else we should inspect and or test? If injector isn't it we'll have to start testing sensors. but it sure seems like a fuel delivery issue.
GLOWING exhaust is typically a Lean Fuel mixture sign.
