Just recently have begun to notice more so when cold that as I first take off from start. It will hesitate,sometimes stall,as I just begin to open throttle takiing off in 1st gear. Bike has 4k on it. I did decide to install fresh spark plugs,no change.
It does seem to run lean at low throttle steady,it does stutter at lower RPM.
I also tried starting out from a stop after clutch is engaged,to suddenly go wide open. The engine acted as if it was running on single cylinder,just for a second then took off. No engine codes have come up. Appreciate any advice as to where to begin.
Tom

 

mine would act similarly, but also unpredictibly... never knew when it would choose to hesitate. in my case, i found that it was running "factory lean". added on a fuel management system and fixed that problem forever! (i am running a tfi techflusion unit- and now have changed the pipes and air sucker too)

 

Sounds like an EFI Sportster that isn't warm yet to me. That stumble/hick up is pretty typical of EFI Sportsters. I have heard some people say that the hickup/stumble is when the EFI switches from open loop (no o2 sensor reading) to closed loop (o2 sensors reading). The o2 sensors don't read proper until they are up to temp.

 

+1 on this, mine (07 roadster) won't run happily for the first couple of miles from cold and then it's like a switch being turned on.

 

Thanx for your response. I hadn't noticed this happening earlier in the riding season. Just seems like something has changed. Tom

 

+1 on all of the above comments.

- They are all too lean from the factory, get a tuner (fuel management system).
- Your Sporty should not be ridden until the motor has warmed up. The cylinders should be real warm to the touch before takeoff. Failure to properly warm up the motor is a leading cause of cylinder and head gasket failures.

 

fixed

 

You should understand whatever (X14Ied, eliminators, etc) you do with your O2 sensors will not affect open loop mode.
Actually, once upon time I wrote a summary of my mods in xlforums - that was before I got fed up with their attempt to make another (financially successful) social network site out of previously technical forums and asked for my account to be removed.

http://xlforum.net/vbportal/forums/s...d.php?t=856532

 

Thanks for looking at my posting, how is the weather in Dublin, OH?