fuel pressure

by bill martin in 912 / 914 Technical Questions 12 years ago

Just finished installing new type fuel pump per service bulletin. Engine runs and starts normally as before. Fuel pressure has jumped to about 6.8 psi with new pump whereas with the old one the pressure was a consistent 4.5 psi. I know the new max pressure is 7.2psi but should I be concerned about this?

Bill.

Re: fuel pressure

by Roger Lee » 12 years ago

Roger Lee

131 5.38k 5.44k

Hi Bill,

That shouldn't be an issue so long as your carbs are in decent shape and the pressure may drop a tiny bit as it breaks in and settles down. This new pump really needs a re-circulation line.

Roger Lee
LSRM-A & Rotax Instructor & Rotax IRC
Tucson, AZ Ryan Airfield (KRYN)
520-349-7056 Cell

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Re: fuel pressure

by bill martin » 12 years ago

bill martin

10 757 0

Found the problem with my fuel pressure. When I changed out the fuel pump, I also changed the fuel line from the pump to the fuel manifold mounted on the balance tube. Apparently despite all precautions, a tiny piece of trash which was either in the pump or in the fuel line, found its way into the tiny brass orifice in the manifold which feeds the fuel return line. Cleaned it out and the fuel pressure is now 4.5 to 5 PSI. Wouldn't have thought that tiny orifice would make that much difference..

Bill.

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