BuggyDepot.com Tech Center 2.0   Categories: All Articles [38] Maintenance & Troubleshooting [3] BDX Install Guides [13] GY6 Performance Advice [3] Service Manuals [1] How It Works! Writeups [5] General GY6 Information [5] Weaknesses & Fixes [1] Modification Ideas [0] BuggyDepot News   Current Status Of Ruckus Swap Kits [Update 8-16-11] Tuesday, August 16, 2011 Front Brake Kits For Yerf Dog GX150 Now Available! Sunday, March 6, 2011 New GY6 Race-built Engine Machining & Building Services! Saturday, January 22, 2011 Overhauled BD Technical Center Released! V2.0 Monday, February 22, 2010 BuggyDepot.com December 2009 Newsletter Wednesday, December 9, 2009 Please note...   Content is copyright © 2005 - 2012 Buggydepot.com PROPERLY SELECTING AND INSTALLING CARBURETOR JETS [15,980 views]   A guide explaining how to properly select jet sizes, and installation on PD24J carburetors. Properly Selecting And Installing Carburetor Jets [15,980 views - 7 comments - Rating 5/5 ] Sizing at sea level: With UNI filter 120-125 With UNI filter and low restriction exhaust 130-135 With UNI filter, low restriction exhaust, A12 cam, performance coil & CDI and NGK Iridium spark plug 135-140 Test procedure: 1. Run engine at less than half throttle a minimum of 15 minutes to close electric choke 2. On a 300' or 100 meter stretch or greater, run the engine at wide open throttle 3. While still holding the gas pedal to the floor, cut the ignition 4. Remove the spark plug and inspect end for color a. White - Increase jet size b. Tan/Brown - Correct jet size c. Black - Decrease jet size 5. Clean spark plug with brass wire brush and check the gap prior to next test run Hints: 1. Change jet size by 2 or 2.5 for fine adjustment by 5 for coarse adjustment 2. Reduce jet size by 2 or 2.5 for every 1500 ft or 500 meters of elevation 3. Stock fuel delivery may not be sufficient above a 130 main jet and may require larger diameter fuel lines and less restrictive fuel filter 4. Once main jet is selected, the air/fuel mixture screw can be adjusted for optimum idle Thanks to PGHRUBY for this writeup! This article has been downloaded 15,980 times 7 comments about this article: Poster #1 [10/28/10] Hey guys! Nice article but i couldn't really decide what size i needed. I got a ''151''cc GY6 with a free-flow air filter, low restriction exhaust, performance ignition coil + CDI + NGK iridium spark, what should i get because i don't have the A12 cam? Poster #2 [11/02/10] x2 on what guy above said, NEED ANSWER FAST PLEASE :) I am running the same setup as Poster #1, and stock gy6 carb to clarify things. thanks Poster #3 [02/18/11] What is the stock jet size for the crossfire 150cc? Poster #4 [03/15/11] Most 150cc scooters run a 107 main jet on a stock setup Poster #5 [04/04/11] what jets do you guys send in your carbs mine are unmarked? Poster #6 [05/30/11] My crossfire 150r was 114 stock, after uniflow filter I went to 120. Runs good at sea level Poster #7 [12/16/11] I am new to the buggy field. i have yerf dog 150 and find your web site as super. i have ordered serveal thing and receive my parts very fast and just what i needed. thanks again for a great web site. Write a comment: Rate this article (no comment needed) 5/5 - Extremely Helpful... 4/5 - Helped me, but not entirely clear... 3/5 - Needs more detail... 2/5 - Should be revised... 1/5 - Re-do this one... Please note: Our staff does not typically provide support in the comments section. For tech support or help with an order, please contact us or visit our online forum. Are you a human? Type "yes": You can rate this article without commenting... Just select your rating and leave the comments form blank!