If the fuse blew then the likelihood is there is either an internal fault in the fuel pump or there is a wire shorting to ground somewhere in the fuel pump loom. If it's conked out again and the fuse hasn't blown I would hazard a guess that whatever was originally intermittently causing the fuse to blow has failed completely not allowing any current to flow.

Nine times out of ten the sort of problem you are describing is the fuel pump motor which has worn out. It is very unlikely that another relay has failed, and I suspect that the relay wasn't your original problem and it was coincidence that it worked after you fitted the replacement. However, I would start with the simple stuff first and go through the wiring with a fine toothed comb. You can also test the fuel pump operation in the dash's diagnostic mode.

I take it you cannot hear the fuel pump priming when you turn the ignition on? Or does it prime, but sound laboured?

The other thing you can do if you can't hear the pump operating is to see if it is getting power by pulling the connector and seeing if there is voltage present with a multimeter connected across the two terminals on the loom side of the connector.

If it is the pump, don't whatever you do look at the price of the genuine part - you'll have a heart attack! The unit can be disassembled and the just the actual pump replaced which isn't available as a Yamaha part. They can be had off ebay for �20-�30 or so.

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