The easiest thing to do of course would be to buy a Dax bottom end since they're balanced very well... even at 10,000 rpm mine had almost no vibration at the bars and seat... and at lower rpm's vibration was non existant...
The next easiest thing to do would be to buy a Dax crank since it's what's really balanced, then buy the skf brand bearings for the crank and clutch shafts, these bearings are way better than stock and with a balanced crank your engine will run very smooth...
If you want to do your own balancing, there are threads in here explaining how to do it, it's not too hard to do but it can be tedious work since it can require a lot of disassembly and reassembly. You will need to drill extra holes or drill starts into the flywheels on the rod side and some have even drilled these holes with the crank installed by carefully stuffing rags or paper towels into the case to prevent chips from falling into the case, drilling into the flywheels, putting the cylinder back on and testing how it ran, this method is all trial and error but effective yet very tedious since you can drill out too much metal.
just search balancing in here and you should find some interesting posts on how it's done...
I will post some links if I still got them in my subscribed threads...
