Hi All,
Just in case this is useful to anyone:
Bike details:
'06 XT660X
'01 ECU
CO set to +10 (up from -18 when I got the bike)
TPS at 16
Idle speed: 1700
K&N Stage one filter
Snorkel removed
Standard pipes.
Found the surging to be pretty horrible...bought Kev's mod - which helped tremendously, but I still wasn't happy...fiddled with CO, TPS and idle speed. Eventually I got it to the point that it stopped cutting out, surging was reduced etc but no better than that. Checked the cush drive - all good there...so definitely fuelling.
Bit the bullet and bought a Power Commander V - the installation was fiddlier than I expected, but certainly not difficult (I am completely non-technical when it comes to bikes). It took me about 90 minutes start to finish, which included removing the Kev Mod, and retrieving the battery negative screw from where I dropped it - into the front sprocket case...
Setting up the PCV was simplicity itself, I imported the standard Dyno map for this model (M412-511.djm) and found a massive difference - surging 99% gone, smoother power delivery etc...a revelation. I also found the transition from 0% throttle to throttle-on became a touch snatchier - I believe this is because the 0% throttle on this ECU leans out the mixture massively, so I'll try adding +5 in the 0% throttle range and see if it helps.
I also noticed way reduced popping on deceleration - I believe the popping is caused by a lean A/F mixture, so that seems an indication that the mixture is closer to optimum.
Most of my daily commute is backroads - sitting in 3rd gear at around 55km/h, or 4th at around 65km/h - both of these spots were hotbeds of surging for me, unfortunately I don't have the PC LCD screen so I don't know what gear/rev combination that is, but after the PCV install that particular spot is smooth as silk.
I did try a few other maps (M412-CaptMoto_smap.djm, kev standard map.djm, M412-505.djm) all available in the XT supporters section, but I found the 511 map was the best for my setup - so that's how it'll stay until I have the cash to get the bike properly mapped.
Once I have it properly mapped I'll update this post with the changes between the 511 map and the custom map. Only problem now is that I really want to go ride the wheels off the thing, and Auckland is just wet and bloody miserable!
Cheers
Grant