Observations: '06 Xt660X & PC V
 

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

I have always said a PCV or PCIII with your own custom map is the way to go if you have the funds, I use a PCV + my own custom Dyno tuned maps on all my bikes.

Using my fuel mod on the XT's uses Yamaha's base map fuel tables & increases the A/F ratio based off those fuel tables, with a PCV or PCIII you build your own fuel tables, you have fuel adjustments in 390 different trim points, on the Dyno we can remap the A/F ratio using these 390 trim points to get the best results.

In the end it is all about the money the more you spend the better the results will be, try & get your own custom map built this will give you the best results.

Definitely - it's just $400 I don't have at the moment...

I bought my XT secondhand with 580 miles on it everything was stock except the Akra cans,it ran Ok but I've tinkered with other bikes and know the difference that can be made and always found it better to do one mod at a time and you know were your going and that includes suspension/brakes etc.

I put a K+N 1 in,then a DNA 2,then Kev's fuel mod,then pulled the snorkel out,then fitted a PC and put the extra holes in the box,the bike runs better with the baffles in rather than out,the motor now runs that well that even when the DNA3 turned up on ebay didn't really feel the need,certainly with the above improvements I never use 1st gear which makes for traffic light GP's interesting.

Their are other improvements to made(weight) but I feel they are in other area's and things get expensive,apart from the obvious of pulling forks up through the yokes and trying various tyre combos.