Richard,
Obviously the max acceptable fuel pressure is determined by the design of the
carburetor
not the pump: a too high pressure may override the float valve and flood
the carbs. Rotax received a lot of complaints about the new pump exceeding
the 5.8 psi limit. It seems to me that instead of finding a technical solution
and rework the pump, they just decided to extend the fuel pressure limits!
Crazy!
One issue is the aging of the carbs. The float needle of the Bing carb is made
of rubber and is subject to wear with engine hours due to vibrations, aging
etc...
new carbs may withstand 7.2 psi or more without leaking but what happens
after 500, 1000 hours? Note there are several provisions designed by Rotax to
deal with carburetor flooding: drip tray drains and airbox drains. This is an
indication that flooding is likely. I think it is safer to stay with the
original
limit. Another thing is to calibrate your pressure gauge as most are grossly
wrong.
Remi
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