Any ideas? recently at wide open throttle (5400 to 5600 rpm) my 200 merc
stalls, like it runs out of fuel. No problem at 5000rpm. It acts the same
off two different tanks/lines. Although I've been told it needs 3/8" line
it has been running on the "original" 5/16. Only change has been a recent
replacement of the stator and the mechanic says that would not cause it to
act the way I describe.

I replaced the fuel pump diaphragm last year. I checked the filter screen
on the engine recently and it only had a small amount of trash which I
removed.

Any other suggestions would be appreciated.
LD