renewing diaphram in fuel pump

[fleathompson]

is it quite easy to renew diaphrams in fuel pump for a 1996 30hp yamaha, or is it best left for a mechanic.my engine does not run well on idle, could this be worn diaphrams in fuel pump. my carb setting is 1.5 turns is this the correct setting.
also at speed it nearly wants to cut out losing revs but is ok when fuel bulb primed again

[mitch]

a complete new pump is only about 30 bucks