New Sportster running rough?

[stro1965]

Not sure how to describe this to make you understand what I mean...

Mama's new Sporty runs awesome when it's under throttle, accelerating.  Seems to almost be starving for fuel or cutting out when I am maintaining low speed through the neighborhood.  I'd say at, maybe, 5-10% throttle?  Just runs rough in that "zone".

My Ultra does it too under similar conditions, but not nearly as pronounced.  Right now it's stock with Cycle Shack slip-ons, I'm wondering if it's needing some fuel.  Is this a Sportster thing?

[PC_Hater]

What gear are you in?
The new rubber mount sportsters have surprisingly tall gearing.

[stro1965]

It'll happen in any gear.  Not lugging.  Just cruising to maintain speed is a pain.  I'm going to pull the Cycle Shacks back off and re-install the factory muffs, see if it smoothes back out.

[andyxlh]

hello mate
if you had a carb I'd say the idle jet was too small of the mixture set too lean, but you have fuel injection, eh? I know nothing about FI, but as it improved with the more restrictive stock muffler I would say that the FI has not been adjusted or is not auto adjusting for the increased fuel flow required at low revs with the unrestrictive cycle shack exhaust. when you change the exhaust on a carby bike you tend to go up a size with the jetting, but I have n o idea how to do this with the FI
also how is the air filter, not clogged? guess it is new!
cheers
Andy
Sydney

[stro1965]

Well, the general consensus seems to be that it's OK to change exhaust only on the newer EFI bikes, that the stock ECM will adjust as necessary. 

All I know is that the bike runs rough with Cycle Shacks so I'm going to switch back to stock muffs to see if that smoothes it back out.  If it does, it clearly needs a Power Commander or something else to compensate for the very open free-flowing Cycle Shacks.

[Panzer]

What year Stro?

[stro1965]

It's the '09.

[96FLSTF]

Hey Stro,
Wife's 05 sporty was carbed so I can't offer any intelligent answers except maybe before you spend extra bucks on a PC or even a T-Max, you might wanna check out Nightrider XiED deals. It'll at least make it run cooler.
http://www.nightrider.com/parts/

Gene

[stro1965]

Well, I had some free time this afternoon so I switched back to the stock muffs.  Same story.  Maybe very slightly improved but, more likely, probably just not as noticeable because it's not as loud.  I think I'm going to ride it to the dealer tomorrow and ask them if I can ride a different Sporty, see if it's the same way.  I'm thinking that it's just a Sportster thing.

[PC_Hater]

My SO has a UK-spec 2008 1200 Nightster.
That has no problems at all. A delight to ride.

[Panzer]

O7' EFI here and no problem.
Let us know what the dealer finds if anything.

[Coasty]

Well, the general consensus seems to be that it's OK to change exhaust only on the newer EFI bikes, that the stock ECM will adjust as necessary. 

All I know is that the bike runs rough with Cycle Shacks so I'm going to switch back to stock muffs to see if that smoothes it back out.  If it does, it clearly needs a Power Commander or something else to compensate for the very open free-flowing Cycle Shacks.

I disagree about the stated consensus, I have worked on many HD EFI sportys and have determined that one bike may be fine while the other sucks canal water.  It is all trial and mainly error when dealing with EFI sportys.  Just be prepaired either use a fuel package or an XiED from Nightrider.