I tried a snowmobile primer bulb and it worked but was kind of slow, tried a couple of swap meet electric pumps that were in a box with other things and they didn't work at all. I am not willing to buy a new one if that is what to expect.  Now I just use a big rubber bulb like 40 years ago.  I will keep my eyes on this thread though because the rubber is starting to crack and I always wanted to try a WW pump myself. A big syringe works good for bladders.  I have heard the big detergent jugs with pumps work ok too.  Never tried one because I don't hink they would seal good enough to keep the fuel fresh.