Noticed a bit of a glitch on my 98 Standard that maybe y'all can help me with. She seems to have a bit of a low rpm stumble. It is most noticeable whenever accelerating from a low rpm in 2nd gear. at about 1500 rpm, and wide open throttle, at first all seems normal, but when she gets to about 3000 to 3500 rpm, she starts to stumble. Not real bad, but definitely noticeable. She pulls through this, and at about a 4000 rpm, it's no longer or at least it's no longer noticeable. She has been ridden some, but due to our typical South Texas monsoon winter (rather than cold temperatures), not as much as I'd like. A couple of other things I noticed that may apply. First, when running through the gears hard (WOT), I noticed or at least I think I can smell gas, and my gas mileage seems to have dropped by a couple of miles to the gallon. I put in a can of Seafoam, and after a little over 100 miles it doesn't seem to have helped yet. Not sure where to start looking.
I had this exact issue and tried seafoam and berrymans both didn't change the slight stumble around 3k RPM. A carb sync fixed it. I think at about 3k RPM you are transitioning from low speed circuit to high speed circuit in the carbs hence slight stumble if carbs are not perfect. I picked up about 10% in MPG's after doing the sync.
Doug E. on the Valky
