08 xb9sx ecm theory

[natez1]

I have a 08 xb9sx with K&N filter and a race pipe and stock ecm maps, runs ok but a stumble of idle and lean surges at cruise.I have been poking around with tuner pro in a before ecm bin and a after ecm bin. both show a pretty rich fuel map with the AFV at 83.1 for both. now my theory is that maybe Buell mapped the 2008- with a target air-fuel ratio around 13.8 or so before the O2 (and other sensors) does it's corrections. Anyway, interesting looking at what they did in the ecm. I am thinking about installing a WB O2 and LC1 and setting to 13.8-14.0 narrow band simulator and looking at how close the maps are. All I need now is time and $$$!

 

[jimijeans]

Yes you will need dollars it all costs money! The Engine runs lean in one area then slightly Rich in another.It is supposed to do that for everyday Riding ability, Depends on what you are adjusting for! The 08+ ECM is a good Delphi Digital 3 ecm used for only the last 3 years of Harleys' sales of Buells.I wouldn't be amazed if Erik Buell is still using some of the Software so as to help Buellers out and keep us Riding.
A little money is OK too! Matter of fact I know he is. Just like the under slung Exhaust. Even Foreign Bikes are following his lead in some areas, he is Right all along! Make sure to save your Stock Program so if you need to go back you can. Make sure to install a wide band O2 for Data logging most EPA target AFV is around 14.1-.4 for Emissions.
Now that depends & is depending on the modifications you may be OR have done. The Stumble off the Start and sometimes at hard Throttle may have a Slight Dead Spot & is Really hard to remove DUE to the Large Crankshaft. Many on the Forum really want the Foreign bike Throttle Blip when downshifting and upshifting. You will find if done incorrectly it'ill pop through the Air Box cause the Engine just isn't Built for that type of use.
Take it to the track properly tuned and she will suprise you with good torQue and balls to the Throttle till she breaks, A stock Engine that is! My 08XB12R pops now and then, when I forget. My Rc51 Honda has 3 dem., mapping and the 4/valves per Cyl.,plus a smooth balanced Crank V-Twin is 90degs.Too much to type! Buells can be Screamers for Track riding like the 09XB-12R I use only for track riding. Took a year or so to Build & Lot of money!
It has never hesitated or poped at all. Harleys could be a screamer if they would just Re-engineer an water cooled 4 valves, XB- V-twin just Simular to that. They need to Water cool all the Engines,most likely they won't for some time. Instead they came up with a Cheap solution w/the Big Twin ECM too hot just let the ECM shut down one Cylinder usally the rear & pump air till it cools down etc.!
But Alas we are the Buell Black sheep. Remember if you go to far with the Adjustments trying to get a couple of extra horses, with Stock inner parts the Engine won't last as long for Everyday Riding.Either way,Welcome to the forum & Have fun but be careful.Good Luck.*Jimi

 

[natez1]

First thing I did was save the stock ecm bin "just in case".I'm pretty sure a guy could screw up some shit with Tuner-pro!My main issue is the lean surges at cruise, not to worried about every last horse, seems the only way to rid the bike of that is a wide-band with controller tuned to a richer mixture because no matter what you do the O2 will always correct in closed-loop.It's funny coming from Harley's myself the reason I got a Buell was I wanted a sportster motor that handled. I like the air cooled v-twin motor but do expect certain things from it, smooth power delivery, fuel efficiency ,and low maintenance. It's just going to take time and $$ to make this happen I guess.

 

[jimijeans]

Yep keep it simple and the Bike will last and handle great once the Suspension is set up for your weight. The Erik Buell Racing ECM I bought one for my Street Bike XB12R 08/and it works really well because I was lazy and I know Erik .
That Said it does have some Very small issues but not enough to worry about.The idle is fast for a longer period of time on Every start, Meaning when you put it in Gear it will slightly grind if the Clutch isn't properly Adjusted should someone try to take off to Quickly before the Idle drops down causing excessive gear wearing and some worried looks at Transmission fluid change time at the drain plug magnet.
Red line seems to work best in a Street Bike Transmission.Amsoil 75/90 works like GOLD! '
I just pull the Clutch and Start mine in 1st and off i go!easily of course! My 09XB12R- race bike I use the programable ECM from Buell Racing due to every Track is different. Sprockets have to be changed different brake pads/ oil changes every 500/miles Transmission Too! Hobby is fun but a lot of work here and there.If you are trying to get it perfect sorry that won't happen due to the way the Engine is Designed. I've been doing this for 34years, Buells are either haul ass OR you Have too finess it in the traffic and Street. You can put an add on fuel pak OR Powerizer/ not a power commander. I've very good luck putting on Vance & Hines for the big V-Twins. Most here don't like the add on Fuel paks but if someone just wants a little bump they do work as long as it is one that will work on a buell ECM.YOU might want to check with Octopus he has some good classes for tuning ECMs. I just put on A Magnum Tuning Sensor from I think the guy got it in Florida but after I installed it Damn/! I was amazed it worked really well. The grin a couple of days later when he came by the shop said it all. Well save your money if possible. While you are deciding Try and Check out Twin Motorcycles.nl they have done a couple of jobs for a friend of mine in California and is pleased with their work. Very Smooth power band, I've ridden his myself over a year ago and the bike works well.Many ways to do what some want and save money for other items on the list. Good Luck!*Jimi