The Carburetor Jet can be a real challenge. The tiny holes in the side of the nozzle can become plugged with varnish, causing carburetor performance to decline, with loss of power over a period of several months or years is undetectable. The tell-tale starting problems will slowly degrade performance, and cause excessive starter wear, and may not be noticed until you just have a hard starting tractor.
This Carburetor jet (Nozzle) is for the John Deere 60, 620and 630 tractors with Marvel Schebler Duplex Carburetors modle DLTX 94 and DLTX 106
An exact replacment for John Deere part R10120R or 47-385