I have had problems with mechanical pumps but not enough to switch over to an electric
one. If you think your pump is your problem, take it apart and check the diaphragm
along with the valves. But before you do that, you should check to see if the fuel line is plugged.
One pump that gave me trouble was the one on my Kohler 7.5kw generator
. It was very intermittent so before I isolated it to the pump, I exhausted a lot of effort and money
spinning my wheels. I took that pump apart and sure enough, one of the valves in the pump proper was never properly seated during its manufacture. I was able to seat the valve by finding a socket that fit over it and tapped it back into where it belonged. Runs fine ever since.
Next, one of my 454 engines had a big problem of randomly quitting without warning. I quickly isolated that to a fuel problem. Took that pump apart and sure enough, I found a valve diaphragm
with a break in it. So the problem was clear, I purchased a new pump in this instance, installed it and now the engine runs reliably.
Too many years ago when I was younger, fuel pump repair kits were available for a few bucks. The kits contained two new valve and a new main diaphragm. No more! We are in a throwaway society today so I think you might be stuck buying
a new pump if the one you have has failed. Pulling it apart does not guarantee an easy fix but it does help identify a failed pump.