Oops, sorry there was supposed to be more than that.
You do have a serious fault tho', the larger fuse will allow more current to flow than the circuit is designed for - you could start melting wires etc - not good!
I would suspect you have a high(ish) resistance short, don't have a circuit diagram to hand but personally I'd start by looking at the horn/brake light switches on the bars.
Do the horn and brake light both still work?
If one of them doesn't then obviously start by suspecting this part of the circuit.
I don't think I'd ride it with the larger fuse, I'd prefer not to have a horn and flap my arms around!!