New-to-me 2005 XB12s, Rough starting, occasional miss on idle, accelerates and runs good though...

[DamnRock]

so I just acquired a 2005 XB12S and I am acclimating to the bike and it's quirks. This was one of those deals where I saw the bike, loved the look, had to have it, and the price was right. The mods, as listed by the seller, are:

* Open air box with K&N filter
* Crank case breather relocation
* Custom exhaust (appears to be stock exhaust, opened up with different exhaust port)
* ECM Spy Cable ????
* Eliminated exhaust valve

Basically, the bike is hard-ish to start. I.e. I start it... it'll idle for a few seconds, then sometimes die. If I give it gas too soon it'll bog down and maybe die. After this happens once or twice, it'll start and I can give it gas and get it warmed up. At this point, it rides pretty good... acceleration is good, rides at normal RPMs pretty well. When letting off the throttle, once it drops down to idle it will occasionally either miss or hesitate, not sure which... but it's a "glitch" in the idle that makes me think it's missing. Doesn't do it any other time than when at idle or on decel. The only other thing I noticed is that I took the bike out for a 15 minute ride and when I got back into my garage and turned it off the fan kept running for a couple minutes. Is that normal?

The bike surprised me when I first rode it, as it's 1st gear wasn't particularly impressive, but damn, 2nd and 3rd gear take off like a rocket! I like the bike, it sounds good (like a harley in a sport-bike frame), rides good, etc. It'll be a great around-town bike.

Any thoughts? I'm not familiar with ECMSPY so I'm not sure what exactly has been done to the maps on the bike yet. I'm inquiring to the previous owner but haven't heard back yet. I'm going to assume with the airbox/filter/exhaust mods that he did a race map or something similar. I'm interested to hear what you guys' thoughts are on what may be causing these symptoms. I'm going to pull plug wires and check for bad connections, worn wires, or water anywhere.

Ultimately, I'm considering putting the bike back to stock (exhaust, airbox, filter), but I don't know if I will like the sound of the stock exhaust as I haven't heard one in person yet.

Thanks for your help!

Rocky

 

[Cooter]

Hey Rocky, Congrats on the new bike!
Being fuel injected, it should start and run easily as long as you understand the little "Harley quirks". This will never be an I-4 Gixxxerwakicbrrukionda.
Starting it cold and idling cold should be easy. If it's stalling by itself, theres an issue.

An obvious miss is a hint as well. Go ahead and check the plugs and wires, but theres another clue you gave.
The fan can (and should) come on when it gets shut off because the temp rises without airflow (driving) so I'd say that's normal. It's a "Sportster" motor blah, blah and Sportsters don't have fans. You'll hear it pinging and rattling way before theres an major issue. Ambient temps and driving style factor into that…

All the gears should be impressive, especially first. These bikes are all about torque. First gear full throttle on warm tires should show you the sky.

Keep the mods you have, they are minor. The stock exhaust sounds like a sewing machine anyway.

I'd veture a guess that you need some minor tuning fixes. It sounds a little lean to me. Perhaps a "race" ecm is your simplest fix?

 

[ich]

record log, post link to log an deeeprom file

 

[DamnRock]

OK, I did a little research on ECMSPY... looks like I can download the program from ECMSPY.com for a small donation ($) and that'll let me record the log for you guys, do a TPS reset, if necessary, and load the race map. Once the cable arrives I'll get the log and EEEPROM file and post them for your guidance.

Thanks! Rocky