Oil Pressure at idle

Posted by bikertucker on Dec 22, 2012; 11:59pm
URL: http://vintage-and-classic-hondas.81.s1.nabble.com/Oil-Pressure-at-idle-tp4034039.html

Have a 1975 CB750 (K5) Once I replaced all the intake boots I could tune engine to idle at 900 to 1000 rpm.Before boots where replaced 1800 rpm was the lowest idle speed it could hold. BUT once I went on a good ride the oil pressure lamp came on at idle, problem had been masked by orginal high idle speed. Connected an automotive mechanical pressure guage. Pressure is good above idle and at rpm's listed in several maint. manuals including Honda manual. Pressure on guage at approx. 1000 rpm is at the 15 to 18 psi range. Reading taken at operating temp. oil is 10W40 full synthetic. Have  inspected and measured pump clearances per Honda manual. All measurements are very good. Replaced all 4 o ring seals, same pressure. Had a spare oil pressure sensor, installed it and lamp remains off at same idle speed and pressure.  Can load engine till almost stalling and pressure dummy lamp now does not come on. Even though lamp seems to be operating normal now, and old unit was  too sensitive I would like to know proper pressure at idle. Want to have a happy engine and not just a happy sensor. Could not find idle pressure in any of the manuals. Have done a search on this site and could not find it either. One person stated 37psi but if I remember correctly
oil weight or idle speed was not given.

Thanks in advance

Tim