Yamaha 8hp 2-stroke fuel pump diaphragm failures

[maddmike]

We tend to use our dinghy only every few months. Almost every time we have bogging-down issues at high throttle that leave us limping back to the dock while constantly playing the choke. Taking apart the fuel pump we always find distorted diaphragms like the attached photo. Installing new diaphragms fixes her right up and she'll run for a few days with no problem.



Are the diaphragms failing because we're in California with high ethanol gasonline? Or because the outboard is stored on the stern rail and in the sun every day despite our infrequent use? Is there some other TLC we don't know about that we should be doing?


Thanks in advance.