Heat seems to be the most common denominator. While ambient heat could factor in, the engine is a lot hotter than the air and the fuel tank is right on top of that heat source. I think the small, stock, steel fuel tanks exacerbate the problem, especially with low fuel levels. When I removed the stock tank to replace it with the Safari, I noticed all the insulation on the stock tank and thought that was a good idea. So I insulated my Safari tank.
The advantage for fuel pump life with the Safari (and presumably with the large IMS too) isn't so much the extra capacity, because most of the additional fuel is carried below the pump, but the the secondary pump that lifts the fuel from the tank wings. The secondary pump is always spraying fuel onto the fuel pump (to fill its little draw reservoir). I think this helps to cool the pump. That and I generally keep the tank more than half full...at least the first half of the ride.
My '08 bike is on the original pump with over 11,000 miles, half of which are off-pavement. I have a brand new fuel pump sitting on the shelf because my bike is in the cursed zone, but I'm not going to pre-emptively replace it. I'll wait till I get stranded in the boonies just to be sure.
Originally Posted by Mikef5000
The only one of those factors that would effect the pump itself is (b). Modifications and riding style make no difference, the pump is either on or off, not variable. Hot climates (or running hot) could be a factor as well.
This is quite common with FI dirt bikes though. A small amount of fuel (which acts as fuel pump coolant), mixed with lots of heat (stuck/slow riding), is going to be bad on a fuel pump, period. Regardless of bike/brand etc.