TILLOTSON HB-15A CARBURETOR SCREWS ADVISEMENT / ASSEMBLY CLARIFICATION
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It has come to our attention that some HB-15A carburetors may have the Low Speed and High Speed Adjustment screws assembled in reverse. It is advised for all competitors to check both adjustment screws to confirm they are in the correct location as shown below. The taper at the tip of the Low Speed screw is noticeably longer than the High Speed screw (left Image) and goes toward the engine side (right Image).
Effective immediately, the Low and High Speed screws will be laser etched with an L and H, respectively. (see image above). To clarify, the recommended factory settings for the adjustment screws are as follows:
- Low Speed Needle (L): 1T 30mins [1.5 Turns]
- High Speed Needle (H) BREAK IN: 2T [2.0 Turns]
- High Speed Needle (H) NORMAL USE: 1T 45-55mins [1.75 Turns – 1.85 Turns]
To avoid further confusion, a free of charge supply of laser marked L and H screws will be made available from IAME USA West and East. Competitors will be able to swap their unmarked screws for marked screws. Customers who have further questions and technical concerns are advised to contact their IAME dealer or importer for more information.