Smoke Screw

[rdodd]

Could someone explain to me how the smoke screw on top of the pump limits the smoke? What exactly does it contact inside the diaprham? Does it change the position of the tapered pin? I was also wondering how it increases the pyro temp 75*on a grade if it is only supposed to affect low end smoke? Thank-you.

 

[BFoster]

The Smoke screw basically changes the spring tension on the fuel limiter, and as you screw it in, the pump is allowed to more quickly go to full fuel(quicker than the engine can burn it, hence the additional smoke). the higher egt's are probably due to the pump remaining in the full fuel posiiton longer when you add throttle to maintain speed, but there are many environmental factors in this(air temp, Wind, Load your carrying, etc)