Which model of RE are we discussing here.....?
Few things to check, spark plug connections, battery connection, you may want to raise the idle by a few 100 rpms (the idle screw is in a well, and if you turn it anticlockwise it raises the RPMs and clockwise lowers 'em). If this does not solve the issue, I will open the spark plug to see its not very sooty, if so replace with a NGK BPR6ES plug. Still not on the spot, take it to the dealer or at least talk to him...