| Author | Message | ||
     Mark_weiss |
'08 Uly Changed plugs and air filter at 10.5k miles. 400 miles later, a hiccup develops. When the bike is fully warmed up, at about 1/8 or less throttle, at about 2000 rpm or lower, there's now a distinct stumble. ONLY under those conditions. Pulling away from a stop, the bike lurches a couple of times and then accelerates cleanly. In traffic, creeping along, the bike will stumble and surge. Idle quality is 'different', but not clearly bad. Checked the plugs, plugwires, & connections. Ran through the '08's TPS recalibration procedure. Am now stumped. Mark in Arizona | ||
| Adrian_8 |
You might try a diff. brand of gas..I found BP Ultimate makes mine run very smooth at low rpms..terrible on Marathon Supreme.. | ||
| Ratbuell |
Wiggle-test your plug wires; if you didn't replace them when you did the plugs, that'd be the first place I'd check. They like to seperate internally, and it can be hard to find if they're not moving around (i.e. they may test fine laying on a bench but as soon as you wiggle it around...). Second - did you use the right plug? 10R12X is the new spec for aircooled Buells 08-up; 10R12 is OEM on pre-08. I'm sure you got it right, but doublecheck your gap as well. | ||
| Mark_weiss |
Plugs are Buell triple platinum. A damaged wire is probably possible, that rear one is hard to manipulate. Are the wires readily removable? I suppose that the airbox needs to be moved aside. I'm going to run this tank of fuel down and try that first. The bike ran fine for a few hundred miles after the plug change, but the problem DID surface shortly (<30 miles) after refueling. Mark in Arizona | ||
| Mark_weiss |
Bad O2 sensor. Related to oil leak. Turns out that the rear rocker box had a small oil leak. The leak was just above the exhaust port and was slowly drenching the O2 sensor. Seems that the sensor does not like being bathed in oil and was sending inconsistent signals to the ECU. Not bad enough to cause an engine light, but enough to cause periodic poor running. Leak fixed. O2 sensor replaced, now the bike runs fine. Fuel mileage went up. IF the mileage drop that I've noticed was due to solely to the O2 sensor, the leak probably started in October. Mark in Arizona |
