How to Rebuild 2003 Arctic Cat 400 Carburetor

Rebuilding a 2003 thru 2004 Arctic Cat 250, 300, 400 or 500 carburetor is the process of restoring or renovating a device on the ATV’s internal combustion engine that is responsible for mixing a fine spray of gasoline and air. Carburetors are mechanical parts that mix vaporized fuel with air to produce a combustible combination so as to convert power into motion. And if the fuel and air are not in the proper proportions, the off-road vehicle will not run correctly.

Rebuilding an Arctic Cat all-terrain carburetor involves removing it, disassembly, assembly and reinstallation. Carburetor inspection and cleaning are also important steps in the rebuild process and those procedures are outlined on this page, see factory service manual for details. It should be noted that the only correct procedures you should ever use to rebuild the carburetor are the instructions provided on this page in the factory service manual.

Download a repair manual: https://www.atvrepairmanual.com/arctic-cat-atv-repair-manual-250-300-400-450-500-550-650/

How to remove the carburetor?

Always turn the gas tank valve to the OFF position before removing the carburetor from the machine, then remove the vehicle’s seat. On the Arctic Cat 250/300 models you must remove the air-intake snorkel. On the 400/500 models you will need to remove the air cleaner housing cover.

Look for the hose that connects the carburetor to the gas tank at the tank’s valve connection and remove it. You will then need to loosen the flange clamps so that you can remove the carburetor from both carb boots. Next take off the screw that secures the throttle actuator cover to the carb, and remove the cover.

Look at the pictures provided. Remove the vehicle’s throttle cable from the actuator arm. Then loosen the nut, termed outer jam nut, that is securing the throttle cable to the vehicle’s carb body. Then position the cable so that it is out of your way. Next detach the choke cable from the carb. To do this you will need to unscrew the plastic choke cable end.

Lastly, detach the vent and gas hoses and remove the carburetor.

Disassembling the carburetor

Follow the step-by-step factory procedures for disassembling the carburetor. Refer to the images to help.

Begin by removing the 4 screws using a Philip head screwdriver to take off the top cover. Take off the vacuum piston assembly from the carb’s body. Do not lose the spring, jet needle or spring seat. Take off the 3 screws that secure the carburetors primer housing. Again, make sure you account for the u-ring (in the housing), diaphragm assembly and the spring.

Next you need to take off the screws that secure the float chamber and remove the chamber. Do not lose the O-ring. Now take off float pin and pull the float assembly up and out of the carb. Do not lose the float needle valve.

See carburetor diagram before continuing with the next steps. Remove the main jet by first securing the needle jet holder with a wrench. Now take out the needle jet holder, then the slow jet and lastly the starter jet. Then you can remove the low speed fuel screw.

Lastly, take out the idle speed adjuster assembly, making sure not to lose the spring and washer.

Assembling the carburetor

Before you rebuild the carburetor, now would be a good time to review the inspection and cleaning section in the manual provided on this page. Check for damaged parts and replace any if necessary.

Follow the assembly procedures carefully using the directions supplied in the .pdf. Also provide are the instillation procedures. If you want to just avoid having to revamp the carburetor or maybe you do not have technical experience needed to repair or renovate the car, you can always pick up a new carburetor for about $65.

Carburetor rebuild kits can be bought for about $14.99. You can use the link on this page to make your selection. Most importantly, good luck rebuilding your Arctic Cat’s carburetor.

Applicable models

The carburetor rebuild .pdf procedures on this page are from the 2003-2004 factory service manual. They apply to the following models with Keihin CVK carburetors...