So after all the fun issues I've been dealing with between faulty 500 H.O. engines (crankcase vent blowing oil into the air box) and CFMoto changing the fix (were back to no fix at all, the latest service bulletin is no longer valid), to having now 4 800 engines blow (3 due to faulty air boxes, 1 to a cracked head which caused the motor to hydrolock and litteraly grenade the front piston and crankcase), to all of the 400s I've sold and have in stock having recalls on the decompression device (hard/no cold start issues), I now have a new fun issue. I'm hoping I can get a fresh set of brain cells to help me find something I'm missing.
I've got a ZForce 800. Rear cylinder is loading up with fuel. The header is full of fuel. The catalytic converter (the fat pipe attached to the back of the stock muffler) was glowing red after a few minutes of idleing. It has no power, and idles low.
I replaced the injector, the MAF, the o2 sensor, the plugs (several times because they were wet fouled), even the ECU. No change. The rear plug IS throwing a good healthy spark, BUT when we pull the plug boot there's ZERO change in the way the engine runs. We have 180psi of compression, so that's not an issue. We checked the timing, and it's dead nuts on.
Any ideas? What am I missing?