Im posting this as information only, as it "may" help someone else. Its going to start an exhaust debate, but here goes anyway.
If any of you have followed some of my posts you will know that I have been chasing the sputter demon for almost 2 years now, unsuccessfully....until today.
Slight history, the bike is a 2006 Ultra Classic with the HD 103 build, 253 cams. Screaming Eagle II mufflers.Since obtaining this bike from my late brother is has been my intent to have it looking and running perfectly. from day 1 the bike has had a sputter between 1500 and 2000 rpm. I have changed several parts, injectors, TPS....the list goes on and on. Maps from fuelmoto for the PCIII installed, everything I could think of. Even had it at the HD dealer..no success. Recently, with the help from a forum member, I located what I thought was an intake leak, so I bought the gaskets in order to replace them. While mulling this over and prowling around ebay, I located a set of CVO mufflers, part number 64769-09. I have always like the look of the CVO mufflers so I bought them. My intent was to install the gaskets for the intake and them have the bike on a dyno to try to tune my sputter problem out.
Anyway, today I installed the mufflers and of course had to fire it up to hear them. The bike hit the first time, idled up and them settled to 1000 rpm. I hit the throttle a few times and noted right away that my sputter was gone. Amazed I didnt even install the gaskets but got my lid on and headed out. Not a single time did the sputter occur.
Got home and parked it, cranked it again a few times and fired right up, no sputter.
So....since the motor is the same as the CVO 103 from that year, could it have been that the exhaust caused the issue and when I put the CVO mufflers on it resolved? I dont know but its gone now. Was it a back pressure issue? Dont know. The bike had the proper HD download (race ) for the build. All I can say is Im finally a happy camper. No, the CVO mufflers are not loud like the Screaming Eagle, but they are deep. Since they are new I have been told that the sound may increase "some" in time, but I actually like them. Not loud but a deep tone.
Anyway....thats my story from almost 2 years. Is it possible?....yep, it happened for me. Is there a reason?....dont know but Im glad it did. and....from gears 1 thru 5 it will now pull the crack out of your ***, lol. Its running like a different machine.
So.....ponder my post, comment, examine, explain....have a good time with it. But it worked on my bike and Im sharing so it might help someone else that is trying to kill the sputter demon.
Thanks for all the assistance here for the last few years......its a great forum.
Best regards and ride safe!

 

That is very interesting, It's good that you run the engine before you change the gasket. If not, you more than likely would have said the the intake leak was the problem. A lot of times people will do multi tasks to correct a problem and never know the real fix. Good job.

 

Thanks! I agree with the gasket question. Apparently when I was testing by spraying carb cleaner around the gasket from behind some must have gotten into the air filter....at least thats what Im thinking. But the mufflers resolved the issue....at least for me.

 

it might still be a intake leak..it might be being masked by the more resrtictive exhaust..ie. the muffler is not allowing as fast of a flow out of it so that the intake velocity has slowed some, so that the gasket doesn't leak....it sounded to me like it only leaked at maximum vacuum pull and that may have been lowered a bit ...I would be interested to know that if you try and tighten the intake bolts if they move or not...

 

Thats an interesting thought, I will give it a try and see. I did test them again, this time using wd-40 and paying more attention. About a 2 second burst of spray front and back..no change in idle.....