Originally Posted by
Glowgeek
When my 5 psi pressure gauge arrives I'll take some pressure line measurements at idle rpms from 2500 to 4000 and report back.
Tank Pressures:
2500 rpm: .04 psi (idle barely reliable but only with airframe at one angle)
3000 rpm: .06 psi (idle reliable but only with airframe at one angle)
3500 rpm: .10 psi (idle reliable and varies 200 rpm up/down depending on angle of airframe)
4000 rpm: .15 psi (idle reliable and stable at any angle)
WOT: .87 psi
I chose to go with 3500 rpm idle for my little vintage champ. Having never run an engine smaller than a .40 I just didn't realize that these little engines need to be idled at higher rpm than their big brothers.
Problem solved! Special thanks to Mr Cox and aspeed for the help.