Hmmmm, well CVH's dont have the best starters and they do suffer with all the heat on the turbo models. Maybe the starter is lazy, dont fork out for a new battery u might not need it, if the starter is stalling it might be shorting the battery out (making the fuel pump noise change). I'd get a bettery test done (with a proper electronic tester not that funky looking contraption they have at motor world ), and go from there

Amazing isn't it, they cost about 12p and are the answer to a number of lifes problems