Sputtering with SuperTrapps

[user 1261]

I have a 2006 that seems to sputter with SuperTrapp pipes with 8 discs and what I believe is stock carbs. The bike had 6 discs when I bought it and 3 holes in the endcap. I replaced the endcaps with the closed ones.
New plugs didn't help. It has 9,200 miles. Any ideas? Should I just take it to a dealer? I am in MD. I had a 2000 for 8 years and never had any sputtering issues. Thanks for your help.

 

[1st Shirt Maxer]

I have the same setup I would first makes sure the carbs are synced and clean. Maybe do the peashooter first. I recently replaced my main jets with 147.5 and my bike started running a lot better. I still have a very minor stumble but it improved dramatically when I put the smaller jet in. I also removed my end caps for a bit the put the old ones back on but drilled an inch and a half hole in them. The sound really woke up and the bike seems like it is more responsive. After checking the plugs after a long ride, it looks like my bike bike is running very neutrally, nice light brown coloring on the plugs. Lastly, check the gaps on your plugs, one of mine was off and I did notice that once I fixed that the sputtering was reduced. Hope this helps.