The stock jet size for the Toyota 4K carburetor typically features a primary main jet size of around 0.015 inches (or 0.38 mm). However, this can vary slightly depending on the specific model and application. It's always recommended to check the vehicle's manual or specifications for precise details, as tuning and modifications might affect jet sizes.
primary jet size 105 secondary jet size 150
80 100
80 and 100
Primary-0.83mm Secondary-1.26mm Idle-0.45mm
Stock main jet on the 2004 yfz 450 is 158.
when i bought my lite ace 1995 GXL model, the stock size carb jets in place were 130 and 160, i suppose this is 1.3mm and 1.6mm respectively. the carb is an aisan model originally fitted to the 5k engine. i have replaced these though with a 120 and 150 size with not much effect on the speed but with a better fuel consumption. some owners i know had have 110 and 130 as their main jets.
The are on the left portion of the carburetor.
120main 38pilot
125 front main 140 rear main
230
JET,MAIN #230137-14143-46-A1 (replaces 137-14143-46-00) this is what was stock.
122 normal 120 high altitude