OS 120 Surpass pumped rich at idle
I have an OS FS-120 Surpass pumped engine. It is the version with the regulator right on the pump, center of the back plate.
It has an issue I can't figure out. It wants to run rich at idle. I have leaned it out as much as the carb adjust allows. And, I received instructions from Great Planes Service that screwing the regulator out would lean the mixture. It didn't. So, I find it is rich at idle and tends to load up. Being pumped, it will not clear the excess fuel when you throttle up. The engine runs strong with a master airscrew 16-6 prop.
Anyone have any experience with this version of the pumped OS 120?