Hi,
Yes TPS: Throttle Position Sensor.
I've got to admit it took for ever to diagnose over here too, from what I can tell it can happen but not often enough for people to look for.
Yes, mine ran like a sack of shit, would struggle with tickover, missing and coughing. It would run smoother at 3000rpm but this rose as the problem got worse, until it wouldn't smooth out till 5000 after a few weeks.
There isn't a way of testing it as far as i know (although the workshop manual may say otherwise if you have something clever and Hondaish).
A
throttle position sensor (TPS) is a
sensor used to monitor the position of the
throttle in an
internal combustion engine. The sensor is usually located on the
butterfly spindle so that it can directly monitor the position of the throttle valve butterfly.
The sensor is usually a
potentiometer, and therefore provides a variable
resistance dependent upon the position of the valve (and hence throttle position).
The sensor signal is used by the
engine control unit (ECU) as an input to its control system. The
ignition timing and
fuel injection timing (and potentially other parameters) are altered depending upon the position of the throttle, and also depending on the rate of change of that position. For example, in fuel injected engines, in order to avoid stalling, extra fuel may be injected if the throttle is opened rapidly.
From this that I robbed from WIKI, if it sends a wrong signal to the ecu, all sorts of bollox can happen to your feuling.
They did a gas analysis on mine which which showed the levels of burnt and unburnt gasses, after they had checked everything else as being fine it left the TPS as the only culprit.
It's the electrical thingy that sits below the fuel rail on the right side of the bike. I think the part as a new spare is hideously expensive, but the one they sourced from a breakers has worked fine for the last few years.
As far as I know they are non repairable, so a replacement is the only answer.
As with everything, this may not be the answer but it's worth a good look.
I'm off to get the nail out my back tyre, it never ends.....
Good luck mate
Mark