YS .91AC Tuning...
07-15-2024, 03:39 PM
#1
YS .91AC Tuning...
Hello All... I'm certain this has probably been covered at some time in the past but, I'm having a tuning issue and can't seem to drill down the the exact problem I'm seeing.
A few weeks ago a friend gave me a YS .91AC. It is low time but wasn't stored well and the exhaust lifter was stuck. No matter. I need a project anyway. I tore the motor down completely and installed all new gaskets and regulator parts. The motor runs extremely well except it is too rich in the midrange. At this point I have the regulator adjuster fully "tight" . There is no more adjustment. I would not expect the engine to run at all adjusted like this.
Going on... While the engine runs well, the main needle is very sensitive - again, suggesting to me pump output is still too high. Just a click or two is enough to make the engine quite rich.
Thoughts? Suggestions? Anyone been down this road before?
A few weeks ago a friend gave me a YS .91AC. It is low time but wasn't stored well and the exhaust lifter was stuck. No matter. I need a project anyway. I tore the motor down completely and installed all new gaskets and regulator parts. The motor runs extremely well except it is too rich in the midrange. At this point I have the regulator adjuster fully "tight" . There is no more adjustment. I would not expect the engine to run at all adjusted like this.
Going on... While the engine runs well, the main needle is very sensitive - again, suggesting to me pump output is still too high. Just a click or two is enough to make the engine quite rich.
Thoughts? Suggestions? Anyone been down this road before?
Last edited by wjvail; 07-15-2024 at 05:57 PM.
