A handy pocket-size calculator which can be used to determine jetting due to elevation and temperature changes. The Use for both single and multi-carburetor applications on two-stroke and four-stroke engines. It also has a guide for determining rich or lean carburetor
conditions. Specificaly for N100.604 and 4/042 jet types, but can be used as a rough guide with all jet types. Sold each.

Mikuni pocket tuner 002-430 $7.20