Question about surging at idle

[riverkayak]

My bike runs smoothly when cold but surges slightly when warmed up. It's a gen 1 super tenere. It's done this since I got it was 16,000 miles. I have the ECU flashed, new plugs and coils. Checker the TB balance and it is spot on. The bike still does it. It runs perfectly smooth when first started, but once warmed up surges slightly at idle. Occasionally it's a little slow off the line. Haven't checked the valves yet, although it did this at 16,000 and now I have about 28,000 miles on it. Any thoughts?

 

[~TABASCO~]

My bike runs smoothly when cold but surges slightly when warmed up. It's a gen 1 super tenere. It's done this since I got it was 16,000 miles. I have the ECU flashed, new plugs and coils. Checker the TB balance and it is spot on. The bike still does it. It runs perfectly smooth when first started, but once warmed up surges slightly at idle. Occasionally it's a little slow off the line. Haven't checked the valves yet, although it did this at 16,000 and now I have about 28,000 miles on it. Any thoughts?

Make sure that (white) hash mark air screw is turned out 3/4 of a turn and re sync.... That is like a pilot jet... If it still does it, try a Chinese TPS sensor... The TPS should NOT have any issues with such low miles... But what you describe Ive seen on high miles and it was the TPS.

 

[Skytower]

Sensors degrade with mileage as well as age. If the temps are far enough off, the bike will run poorly as it sets the wrong fuel delivery.
Watch the coolant temp and air temp readouts as the bike warms up. Verify the temps, if you can, with an IR gauge.

If not a temp issue, and all the regular maintenance is up to date, check for unmetered air: loose clamps, cracked/cut rubber hoses. Use short sprays of carb cleaner near suspected leaks, and listen for a change in RPM. Just keep it away from the intake

 

[Tenforeplay]

Mine does the same thing. I attribute that to the a/f ratio. On cold startup, I assume it is operating on an enrichment table or other, but richer than the 14.7-1 idle the narrowband dictates. Prior to complete warmup, it comes off the table and runs a little lean. Prior to the ecu flash, fluctuating idle was worse. The ecu flash using the hulk tune smoothed the idle ignition curve so I imagine the engine is not hunting for a happy idle rpm, or not as bad as previously. Mine is a gen 2. The gen 1 can get around the narrowband dictated 14.7-1 idle ratio by changing the O2 numbers I believe, richer idle ratio would help imo. Or someone could dive into the tables and see what the enrichment factor is and if it wasn't too bad set the parameters to run under idle enrichment, but that may bet into carbon buildup problems if too rich. Running under sport mode may help alleviate some of the nuances.

And I will add, changing ignition timing changes the a/f ratio the engine sees. So at idle it is kind of important for a steady ignition timing, which the oem tables don't show.

 

[NickFWN]

Any update on this idle issue?