Originally Posted by roger 04 rt
Alainmax, Just before 1 bar it is Open Loop AND richer mixture. Often, the richness (only a few percent richer at that point) makes a big difference.
What I think I'd do if I were you would be disconnect the O2 and add temporarily an AIR TEMP. Shifter like BoosterPlug or iice air. I have one you can borrow for testing. Does your fuel have ethanol in it? If so is it 10% like I get here in MA? Adding the air temp shift in open loop will keep the mixture a few percent richer. I don't recommend it as a long temp solution but it may give you a lot of insight.
What we want to find out before you spend money on a new o2 sensor is how sensitive your bike is to its mixture.
thank you Roger,
My mistake : i keep forgetting to include this info . : i have been running the booster plug for 3-4 years !!!