Baron Air & Fuel_PILOT MIXTURE ADJUSTMENT SCREW - Yamaha Road Star - Manual

Page: 1 BA-2150-00 & BA-2150-30
Pilot Mixture Thumbscrew Installation
Revision: 1.1 - 02/21/2013
INCLUDED IN THE KIT:
(1) - Sheet Metal Screw
(1) - Drill Bit
(1) - Adjustable Pilot Mixture Screw
INSTRUCTIONS:
1. Remove carburetor(s) from motorcycle and drain the fuel from the float bowl.
2. Locate the pilot mixture screw (PMS) plug if the PMS is already uncovered on your carb, you will see a
recessed screw head located on the bottom or side of your carb. Remove this screw from your carb. Remove the
stock spring, o-ring and washer from the stock screw, noting their position and sequence on the screw.
3. If the PMS is still covered with the factory seal, you will see a brass or aluminum plug with a small hole in the
center. Proceed as follows: a. With supplied drill bit, carefully and slowly drill through the pilot mixture plug.
CAUTION: The fuel mixture screw is located directly beneath this plug. Be prepared to stop the drill and remove
the bit the instant you break through the plug.
b. Insert the self-tapping sheet metal screw into the drilled hole and carefully remove the plug. With the PMS
now accessible, remove it from carb. Remove the stock spring, o-ring and washer from the stock screw, noting
their position and sequence on the screw.
4. Place the spring, o-ring and washer on new Baron Adjustable PMS Thumbscrew and install it into the
carburetor, making certain not to damage metering tip of screw. Slowly turn screw clockwise until it seats
lightly. Now back out screw the same number of turns that you would the stock screw, according to your jetting
instruction and air/exhaust set up. Apply a color mark on side of screw-head for turn reference.
5. Reinstall the carburetor(s). We strongly suggest that you attach the throttle cables prior to mounting to
intake manifold. Reconnect the fuel line, ensuring the clamp is firmly in place. Reinstall all vent hoses and
electrical connectors that were previously removed, checking for any obstructions or blockage. Note: It is
important to verify proper throttle operation before starting the engine.
6. Verify that the PMS adjustment screw has been set to a starting position as described above. Check the
engine at idle speed for any popping or back firing. For best results, warm bike up to normal operating
temperature. Adjust idle to factory recommended setting. Turn PMS in slowly until engine starts to miss. Now
turn screw out until idle is smooth. Perform this step to the other carb(s) as required. If you find accessing the
Thumbscrew difficult, you can place a rubber extension" hose over head of Thumbscrew for easier access.
Our install guides provide a basic outline on the proper installation of our products. Further tuning and/or
fitment may be required. Barons bears no responsibility on installation costs associated with this product.
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5221 Oceanus Drive Huntington Beach, CA 92649 (925)583-2499 - Ph. (714)901-0520 - Fax www.baronscustom.com [email protected]