PK-1B Tillotson GX200/Clone/Predator 212 Stock Carburetor
The well-known, world leader in small engine racing carburetors, Tillotson LTD, has produced their version of the common GX200 carburetor. Tillotson recognized the need to produce a consistent carburetor for the USA clone racing engines. The engineers took the 196cc OHV lawn and garden carburetor and calibrated (Blue-Printed) it for the racing market.
The improvements over the PK-1A are primarily in the casting to the liking of the rule committees for approval while improving flow to equal or exceed the best quality Ruixing and Huayi Carburetors. This carburetor is the closest out-of-the-box setup that meets the performance of most blueprinted carburetors. To make the most of this design we built it to handle larger bores that the average stock carburetor. This is the preferred carb body for the best stock appearing carburetors.
The key standard features:
• The venturi is machined to .613" plus or minus .001" very close to the .615" no-go rule. Additional boring is not needed.
• The throttle shaft alignment is made to the centerline of the bore.
• The emulsion tube is of a 24 hole progressive design
• Main jet size .039"
• Low side jet .028"
The jetting above is a general starting point for all different types of racing, this combination was base on a stock rule clone using CL-1 camshaft turning a max RPM of 6,100 with 10.8 springs.
If you have a current 2019 built AKRA stock clone engine with ported head, CL-3 type camshaft 10.8 spring, 32 degree flywheel advance
and your turning about 7,000 RPM or more you may find using a .032" to a .035" low side jet and .034 to .037 main jet. Caution: Using this combination your idle maybe rough and there is a chance of loading up if it idles for too long
Mini bike racers we recommend trying the carburetor as is , if idle is too rough you may need to purchase a .020-.024" low side jet.