Backing off star screw to reduce off boost smoke

[jackbombay]

Right now I am in Idaho at 6300 feet, my buddy has a 93' cummins that lets go a cloud of black smoke when he takes off from a stop. but does not smoke at WOT. A simple star screw adjustment (top center of boost enrichment diaphram) will reduce this smoke, right?

[malone]

Right now I am in Idaho at 6300 feet, my buddy has a 93' cummins that lets go a cloud of black smoke when he takes off from a stop. but does not smoke at WOT. A simple star screw adjustment (top center of boost enrichment diaphram) will reduce this smoke, right?

Yes, that's the way to do it with minimal sacrifice to fueling in the top end/WOT. At least that's how it worked in my 1.6TD.

Raising the starwheel up (by screwing counter-clockwise) will increase spring tension between the starwheel and the boost pin diaphragm. If the spring wasn't already stiff enough before, this should reduce smoke during off-boost or low-boost.