13-09-17, 10:19 PM
Running poorly after rain is usually water getting in around the spark plug caps and then you lose spark due to arcing to the engine. If you've still got the original Yamaha spark plug caps it's probably time to change them. There's an NGK cap SD05F that will work on the Fazer and they are very cheap so well worth getting. That should solve most of the running problem. If your carbs are over flowing it's probably a float valve, float height, float seat or o ring under the float valve seat that is the problem.