What rpm are you holding it steady at?
I have an '03 XB9R with a race ECM, race exhaust, and K&N filter. It has new E3 plugs and I just reset the TPS and it's still doing it. The bike will accelerate very nicely, no stumbling or anything, but when I hold the throttle at one position to try to cruise, it starts cutting out and jumping around on the RPM's. The bike idles at 1100 RPM and it's fairly steady. What else could this be? I was thinking maybe a foreign map on the ECM could cause this?
What rpm are you holding it steady at?
About 2800, it cruises really nice sometimes and then other times it'll sputter and jump around.
That's a pretty low cruising rpm, I'd expect a little bit of finickiness around there. Run it up a bit more or drop a gear.
If you want to change something, replace the TPS.
That's darn close to stall speed on that bike.
Minimal should be around 3500. Cruise would be above 4500.
It's not your typical Harley twin design. Keep that in mind.