All of sudden my SV1000S K4 started running rough at 3-5t rpm range, while having constant throttle at cruising position (~10%). It is literally kicking back and forth with the whole bike and it appears even in neutral. Actually here is the sound...most noticeable at 20-30s as misfires/little pops:
Vocaroo | Voice message
When the issue kicks in, the STV move/jump around quite significantly...but not really sure, if that is the cause or consequence of a problem...yet seems important.
Last time I rode her everything was fine (2 weeks ago), on this Friday the issue appeared immediatelly and getting worse with warming up the bike.
PC V, O2 sensor gone, stock headers, STORM/MIVV cans, K&N filter.
Moved with spark plug cables and PC V ignition harness.
Removed quickshifter switch from PC V temporarily. QS itself is working.
Checked intake for vacuum leak - exchanged a cracked rubber cap and tightened one little loose airbox clamp.
Did synchronization of throttle valves + TPS and STV adjustment.
Tried to completely mis-adjust the STV sensor.
Nothing helped so far. Will try:
Different PC V maps or tweak fuel in the affected range...to rule out bad tune. Yet both maps, I have used before, were just fine.
Check for vacuum leak in Scottoiler vSystem...as I didn't focus on this part yet, it is few months old.
Pretty sure the TPS and STP are OK, so I will re-do the synchronization again....while swapping hoses for more precise measurement.
After these I am out of ideas, so any other suggestion is welcome. Thanks in advance.