I don't want to get drawn into the ifs and buts, but here's a timing map for the TDM, showing ignition advance VS throttle %. Clearly there's a big red patch , starting at just under 3000rpm, where the timing jumps to 56 degrees of advance at small throttle openings, and the blending off for wider throttle openings is very steep.
http://i.imgur.com/cudGLsK.png?1
It's pretty clear to me, from observation through riding, from playing with the timing, and from playing with other variables that the timing is indeed very unsmooth, very 'blocky'
A lot of people complain about a surge at about 3000rpm which make it difficult to ride in town.....and those people weren't imagining it, once the ignition map was recovered it was pretty clear what the main contributing factor was. (I didn't recover it, that works was a joint effort by several well known tuners, who figured out that the ECU in the TDM900 is the same Denso 16 bit unit used in Early GSXR 600's and many other bikes of the day, such as the early R6 and R1) . It is not an ECU which as some people might think is a crude primitive device, it even has Alpha-n throttle control where the rate of change of throttle is used to increase fueling proportionately. A quick twist of throttle to 50% causes a greater surge in fueling than a slow change to 50% throttle....this mimics the accelerator pump of many carbs.
Samios don't share their map (for obvious reasons) , but it is smoother in the same region of interest, the throttle has a more linear response.
Edited by fixitsan, 02 August 2018 - 07:37 am.