Well, a couple thoughts. Normally backfiring/sputtering is a timing issue. On electronically controlled engines, it's most indicative of a faulty sensor. My first stop would be disconnecting the speed sensor (if Vic's have one) and take it for a ride. On cars, some of the systems are adjusting timing based on speed. See if your symptoms go away. If nothing changes, check your crank position sensor and make sure the end is clean (doesn't have any sludge build up). There should be a test to spec the CPS. I'm familiar with inductive CPSs that usually have a voltage cycle but I'm not sure if that's Victory's setup. They usually require you to rotate the engine while reading the voltage. Some you can simply ohm out. I have a manual for a Vision, I'll have to take a peak at it.
Beyond that, I'd look at the ECM, but I wouldn't worry about it at this point. I've read several issues with Speed Sensors on Vic's. Start there. There are plenty of other possibilities too, but some of them are much more involved but unlikely at your mileage. Of course, I'm sure there are many people who actually know their way around Victory's so I could be off in my recommendations. Those are purley general mechanical thoughts.
Last edited by rcb; 07-19-2013 at 06:17 PM.