rough running

[Don p]

looking for some help my 97 valk seems to break up between 3400 rpm and 4000 rpms after that it is ok

[pancho]

Try running a can of Berrymans B12 through the it Don, if that doesn't make any difference, I would be looking at removing and cleaning up the carbs.  Welcome to the world.

[gordonv]

Apply half a can of B12 to half a tank of fresh fuel. Run the bike at high gear/low speed (low RPM) for a distance. Let it sit.

Next day, same thing.

Ride it in the RPM range that it gives you trouble. Same thing, ride it for a while, then let it sit for a while. This is to get the "formula" into the jets which are giving you trouble, then letting it sit will allow it to act on the problem circuit.