R.E. Kev's Fuel Mod on my XT660
 

Hello Right got kevs fuel mod and the controller, set it up as described and took it down to a dyno today and was slightly confused, ill give you a breakdown of my bike

XT660 - 2009
K&N Air Filter stage 1
Snorkel Out
Kev Fuel Mod and 02 Controller
Akrapovic Half system with Cans baffles out

when set up and running on the rolling road it was running very lean, adjusted kevs fuel mod to about 3 o'clock as recommended in the instructions for the set up that I'm running, now in order to make it richer we had to re introduce the snorkel and have the fuel mod turned all the way up to 12, it was only then we were getting a healthy reading off the dyno but obviously we lost a little lean power.

Any advice on this ? anyone else running a similar setup, or have any advice that they could share please? ill attach the dyno printouts if i can figure out how to add them.

any advice would be massively appreciate it

Pictures R.e the above post
 

http://imgur.com/a/XzGJp

First, a question...

Did you block the AIS pipe before you ran the bike on the dyno?

If you didn't, you will get very lean (and erratic) readings of A/F ratio.

Just seen the dyno graphs! They are some of the weirdest looking A/F lines I've ever seen?

Where did you take it? Seastar Superbikes?

The torque looks about right though, which means it can't actually be running at 17.5:1 otherwise it wouldn't make anything like that. The spike in the A/F reading could be the AIS valve opening giving the exhaust gas analyser a false reading?

Was it blocked or not, that is the big question...

Wasn't aware there was an AIS, the mean fueling was lean though, the ais surely would only account for where the emissions tests would be undertaken on the bike ? Can i get a rough idea how i should have the airbox and kevs mod set up please, cheers for the help by the way! and yeah it was Seastars, any idea what BHP/FTLB i should be looking for with this set up ?

The AIS operates under various predetermined conditions. Most common condition is when the throttle is snapped shut, which wouldn't necessarily affect dyno A/F readings, but the AIS valve can open for other reasons. For example it is fixed open until the engine is fully warmed up.

The biggest problem with the AIS enabled on a dyno is you (the operator and the dyno machine) don't know what it's doing. In order to have an effective dyno session and build a good map the AIS needs to be taken out of the equation. Seastar are reputable dyno tuners, so I'm a little surprised they didn't clamp the AIS pipe before the first run?

To block the AIS read this thread:

http://www.xt660.com/showthread.php?t=5544

As for the power/torque it varies from bike to bike and different dynos read differently. Really you should only take not of your figures for tuning purposes and for comparing different mods on your bike. However, as I said earlier, your torque looks good, if a little lower in the rev range than I would have expected. A stocker makes 56Nm(41 ft-lb)@5500rpm, so yours making 46 ft-lb is an improvement, but it did peak at 4700-4800rpm.

Something's not right though. 17.5:1 is extraordinarily high. Besides blocking the AIS are there any air/vacuum leaks? One thing that does give ridiculously high A/F ratios is a perished throttle body to cylinder head intake hose. It's not unheard of for them to go porous even on relatively new XTs. Modern fuels containing ethanol give rubber parts in the fuel system a hard time. What's it look like? Any cracks? Any bubbling?

It might be a good idea to join the Supporter's scheme for a tenner and then you can post a query in the Ask Kev section. He's put more XTs on a dyno than anyone and will be sure to have more ideas/suggestions than I can offer. The link to join is in my signature line.