View Full Version : stock 400ex putting on a hmf slip on and what should i jet it
02heavychevy
02-13-2010, 06:39 PM
i have a completly stock 400ex and i am putting on a slip on Hmf and i am at 600 feet above sea level and i want some ideas of what my jetting needs to be. do i need to change my pilot jet or just the main
CarGuy7a
02-13-2010, 07:52 PM
Usually the pipe will come with a sheet and it should have a recommended starting point for jetting.
Me personally I would put in a 155 main. You don't have to change the pilot from stock, but if you go to a 40 pilot jet with about 2 1/2 turns out on the air fuel screw, it will help cold starting. Some say a 42 works better for them but I tried a 42 pilot jet and it was way to rich for my quad.
When I bought my White Brothers E2 pipe they recommended 3 turns out on the air fuel screw with the stock pilot, which did work, but it makes the screw dangerously close to vibrating and falling out of the carb.
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