Small Engines (Lawn Mowers, etc.): kohler fuel pump, facet fuel pump, horse power engine

Question
I have a 1983 model Kosher rv genset (3.5CM21-RV) powered by a K181QS Kohler motor.  It has a Facet fuel pump which needs to be replaced (41 393 28 which crosses over to a 41 393 45s).  I'm trying to determine what psi this pump operates at so that I may replace it with a like unit from a source other than Kohler.  I figure it is a pretty low psi unit but would like to positively identify it.  Appreciate any help.

Answer
Gary, I am not sure of the exact pressure of this particular pump without some time tracing down manuals for this model, I don't have one here at the shop this moment. But most pumps used on this horse power engine are low, usually around 1.5psi max.     Tom