2006 KQ 700 running lean...
Looking for some help with my 06 KQ 700. Bought it needing some work. Fuel pump was bad and compression was a touch low. Put rings and a high compression piston in and replaced the fuel pump. Ran well after but was a little rich and would foul the plug after about an hour of riding. Tested fuel pressure and it was a little high - it was an aftermarket pump that I guess are notorious for being plus or minus the necessary 43psi. Did the o-ring trick and got the pressure to 43 psi. Ran correctly for a day then started leaning out and backfiring and stumbling. TPS was not allowing for any adjustment so I replaced it and got it set to the middle reading. Checked fuel pressure and the pump was initially hitting the necessary pressure and then falling off. Read some comments online that some of those cheap aftermarket pumps can go bad pretty quickly so I ordered a replacement. The first night I put it in, ran great. Parked it and went to load it up the next day to go use it and it started running lean again. Doing the same thing it did before. Wondering what your thoughts are. My suspicion is that the computer is making a fuel pressure adjustment, thinking the engine is getting too much fuel. Not sure what else it could be at this point, but it's frustrating as all get out. Thanks in advance!
Edit: No F1 light has ever shown up and I've gotten no fault codes.
Last edited by saleenmav; 08-13-2019 at 09:29 AM.