After a few days/hundreds of miles of removing and reloading/replacing a (any) map for my '08 SDR, the fuelling slowly deteriorates from smooth, responsive and glitch free throughout the rev range to very lumpy low rpm (feels like it's bogging down) and significant flat spots/on-off snatchiness usually bang on 3k, 4k and 5k rpm irrespective of gear/throttle position - have tried all the available maps and, aside from the fact that they all appear to fairly rich, all develop the same symptoms - 15 min reset improves fuelling but only temporarily.

All sensors, TB motors, etc are bang on spec, either OE or those proven to be better, and currently running Joker's map with (Moto's) secondary flies (but not shafts) removed , OE airbox with K&N filter, O2 eliminators and round Akras without baffles.

I have no idea why the ECU appears to be (re)learning bad habits after a short while, other than the fact that I run in and out of London every day (75 mile round trip), ie half the run with a lot of stop/start, small throttle/low(ish) rpm, etc and that, from memory and I'm not convinced it's relevant, this problem has developed only since replacing the OE secondary flies with Moto's, at which point also fuel consumption/richness increased significantly.

Other than replacing the OE flies to see what happens, any ideas?

Check intake rubbers for correct sealing and or cracks in the rubber, an air leak cant always be seen when the motor is cold but may apear when its hot... e.g. 15 minutes into your ride....

other than that it sounds like the problem is on the open loop circut so maybe try re-attachement of 02 sensors just to see what the results are

Thanks for the suggestions - have had leaking TB rubbers in the past, 'only' causing tickover problems, and the TB's have been on and off several times since this changing fuelling problem started - not sure how/why reconnecting the O2 sensors may help though - but will check/try both suggestions - logic says it may be due to the removal/replacing the flies but I cannot see how.

So much here No. 47 ... bike mileage info can help. Ever check the valve clearances? Intake Air pressure and Temperature sensors all well? Fuel injectors - all good there?

Do the O2 eliminators provide a constant voltage reading to the ECU, unlike the O2 sensors?

If so, the eliminators may be telling the ECU to constantly run rich below 5k rpm which the ECU slowly 'learns' which in turn results in the gradual deterioration in fuelling...................?

How does TuneECU switch off the O2 sensors/eliminators?

I have found exactly the same as you; it can be perfect in the morning but crap on the way home. Also seems to gradually get worst.

Have you had your fuel filters changed ? I'm going to try this next - although they aren't cheap.

Something else I've found is that it behaves better on a full tank but then gets worse as the fuel level goes down; which is why I'm thinking maybe fuel filters.

My bike is an 08SD with 21k miles on it running Akra map O2's and SAS turned off.

I'm approaching 40k miles and checked fuel filters at circa 20k miles - pretty clean then and, for me, unlikely to be causing this long term problem given that the deterioration is gradual over several hundred miles - running well in the morning but worse in the evening is a familiar one but usually on days with cold mornings and warmer evenings and I fill up practically every day and fuel level does not noticeably make any difference - better running in cold dense air would indicate permanent fixed over rich fuelling - a custom map is the obvious answer but this would also be 'overwritten' in time if there's a constant rich message from the 02 eliminators and/or the TuneECU O2 'off'.

Your symptoms could be caused by dirty fuel filters though.

Little off topic...

Props to you Brits. 20K, 30K, 40K miles? I'm impressed. I lived there for 3 years and could not imagine putting 10-15K miles a year on a street bike with the weather you guys have to deal with.

Good on ya!