I believe I have an identical generator. Is that a Coleman Powermate 1850?

specs say 3600rpm

Standard for small, non-inverter generators. 60 cps (hertz) times 60 seconds in one minute equals 3600. As generators get larger, 1800 rpm is also common, with two cycles per rotation. Hoover dam generators turn at 180 rpm, producing 20 cycles per rotation.

manualsdump.com has a manual available for that model.

Edit: It is the same model as mine, Coleman PM0401853. I checked back to your original post and noticed that you included the model number there. I'm the guy that recommended the "jerry-rig". I didn't know at that time that I had one like it. My parts diagram shows this as the replacement spring.