Last year i had a couple of electrical problems probably connected with having a lithium battery fitted to my 2007 1098. i removed the airbox and inspected everything including a leak at the front fuel injector. i did notice that there was a small build up of black stains on the valves near the stems in the front cylinder. Was advised to use some valve cleaner and never though much about the rear cylinder until i disconnected the exhaust system to give it a clean and polish. everything inside the rear cylinder was black with soot. i also noticed that a plastic plate had come loose inside the airbox, so i cleaned the edges and glued it back into position. Could this loose plate be the problem for the rear cylinder turning black with soot since the bike had the shims done in 2020 ? . the plastic plate has a hole cut in it to allow fumes from the gearbox to escape. the plugs were renewed and the bike only did 50 miles last year due to knowing about the fault. when i used the bike it ran ok until the revs dropped and it cut out.
Is it not just more likely the rear cylinder is running a little rich ? Check the plug would be the first thing I'd do. As stock the maps are not cylinder specific. Most good tuning shops will map a per-cylinder fueling solution.
Well worth checking that the fueling is correct for both cylinders, and if not finding out why - faulty injector sensor etc. That amount of soot suggest excessively rich running. 1098s are prone to piston cracking if the fueling isn't right. Ask me how I know...
I don't know tbh. But I had that problem on my 1098 SF. Yours appears to be substantailly over-fueling on one cylinder and it warrants investigation.
just read some of my older posts on the subject and the mechanic said the TEXA came up saying the TPS needed resetting. i reminded him that if the tps is reset it would then need re-dynoed . he said that the adaptives had been reset electronically. i will check the plug just incase its faulty
