Difficulty Level

Tools/Supplies Needed:

• 220 wet/dry sandpaper
• 400 wet/dry sandpaper
• 600 wet/dry sandpaper
• 1000 wet/dry sandpaper
• 1500 wet/dry sandpaper
• -2000 wet/dry sandpaper
• bucket of water
• screwdriver
• rotary tool (Dremel)
• grinding stone for rotary tool
• 80 grit drum sander for rotary tool
• felt wheel for rotary tool
• penetrating or cutting oil
• metal polish
• soft cloth
• carburetor cleaner (used in the video is Permatex Throttle Body, Carb & Choke Cleaner #80279)
• thread locker (used in the video is Permatex Permatex Medium Strength Threadlocker Blue #24200)

Procedure:

• the carburetor and intake manifold must be removed from the engine
• clean the carburetor and intake manifold before the porting and polishing process so we won't have any contaminants
• keep the carburetor disassembled as we will be cleaning it again after it has been modified
• remove both the choke and throttle butterflies by removing the small standard screw for the butterfly plate, then pull the plate out, and slide out the shaft
• starting with the choke side, normally this isn't a critical side as we don't have to worry about the idle being affected such as the throttle plate area
• start with 220 first, be sure to always pre soak the paper and wet the surface down
• rinse the area off when an access amount of sanding debris builds up and then continue wet sanding
• wet sand until the casting is fairly smooth
• move onto 400 grit and gain the same process, pre soak the paper, then keep the area well lubricated with water
• rinse away any excessive amount of sanding material build up
• once satisfied, move up to 600 grit, then 1000 grit, 1500 grit, and finally 2000 grit using the same process
• next step doesn't apply to all carburetors unfortunately as it will depend how your air filter side is designed
• I am able to flare out the opening to allow for more air flow, by using a rotary tool and a rotary stone
• apply some penetrating or cutting oil to the aluminum surface and the stone, then flare out the opening, keeping it on a lower speed to reduce any debris splatter
• finish up flaring the opening with the rotary tool and drum sander to smooth out any rough edges
• wet sand the flared opening starting with 220 grit, then 400 grit, 600 grit, 1000 grit, 1500 grit, and 2000 grit sandpaper
• moving onto the throttle plate side, do not bore out the opening, we only want to smoothen the open
• first match the port opening to the intake manifold or engine block by using a gasket and paint market to trace the opening
• if they are poorly matched, use the same process as what was used to flare the carburetor opening
• depending how rough the surface is, you can start with 1500 grit wet sanding, as for me I used 2000 grit wet sanding
• using a felt pad for the rotary tool, apply your choice of polish (I used Eagle One Original Mag & Aluminum Wheel Polish) and work the product into the surface
• apply more product if needed, then wipe away product with a cloth once done
• for the shafts and butterfly plates, wet sanding them using 2000 grit sandpaper
• if the plate is steel, you can start out with 1500 grit wet sanding and finish up with 2000 grit
• polishing the shafts and butterfly plates using polishing compound
• match the ports on the intake manifold if not done already using the gasket method
• start with the grinding stone on the rotary tool, remove the rough casting
• ball hones can be used as well to access the hard to reach areas
• once satisfied, move onto the 80 grit drum on the rotary tool to smoothen the grinder casting
• re-clean both the carburetor and intake manifold
• reassemble the carburetor
• for the butterfly plate fasteners, I would recommend using a thread locker