The jets numbers are simplely the hole diameter in milimeters X 100. Here are some measurements that I took with a set of hole gauges;


Jet # Dia (in) Dia (mm) dia mm X 100


116 0.0455 1.1557 115.57
118 0.0455 1.1557 115.57
120 0.0465 1.1811 118.11
122 0.0475 1.2065 120.65
124 0.0485 1.2319 123.19
126 0.049 1.2446 124.46
128 0.0495 1.2573 125.73
130 0.0505 1.2827 128.27
134 0.052 1.3208 132.08
138 0.0535 1.3589 135.89

The close sizes show why Bubba and his 1/2 in Black and Decker cannot "drill 'em out" with the old drill set. The number drill sizes jump several thousands between sizes at these diameters.

Bob

 

That is correct for standard jets however Dynojet #'s are relative to the amount of fuel they flow in cc's


If you ever drill out a jet have the common sense to file or sand off the jet size so you don't F yourself at a later date

 

The jets that I measured were from a fresh Dynojet #214 kit for my V-force.

Bob

 

Various carb makers use different references for their jets. Some hole size, and others fuel flow. I had a 700 cc 2 stroke sled with Keihien hex jets, I ran I believe 180's. The next year I get another new sled but the manufacter had switched to Mukuni carbs. The neww 700 cc motor was now running 450 Mukuni jets.