Mikuni Carburetors

Mikuni HSR Kit for Harley

Mikuni HSR Kit for Harley
Mikuni HSR 42, 45, and 48 Carburetor Kits for Harley Davidson
Mikuni has followed up on its successful HS40 Carburetor with the advanced technology second generation performance carburetor called the HSR42. The designation HSR42 denotes a smoothbore racing carburetor with a 42mm venturi for Harley-Davidson applications. The HSR42 and its big brother the HSR45 were designed with a larger body assembly to fill the need for bigger throttle bores in all-out performance applications. Mikuni designed the new HSR42 carburetor with a smooth pulling 8-roller bearing flat throttle slide assembly. The flat throttle slide design allows an unobstructed venturi at full throttle to flow more air, and it carburetes more precisely at all throttle settings. Most aftermarket carburetors use butterfly throttle valves which obstruct the carburetorís venturi at all throttle openings, creating airflow turbulence and hindering precise air/fuel metering. Mikuniís roller bearing throttle slide offers smoother control and allows the use of a lighter throttle return spring for reduced throttle effort. Flow bench tests show that the new Mikuni HSR42 and HSR45 are able to flow more air to the engine once installed on the manifold and head than other models of aftermarket big-bore carburetors.
This is because other big venturi carburetors have that restrictive butterfly throttle valve which disrupts and hinders air flow. The HSR42 actually flows more air at full throttle to produce more peak power than other bigger carburetors. While at smaller throttle openings the Mikuniís smaller, yet higher velocity flowing venturi, together with its advance fuel metering system provides a stronger overall power bank with improved ridability. The HSR42 is also the largest performance carburetor on the market to meet the requirements of the California Air Resources Board for installation on 1340cc Evo model Harley-Davidsons. Other performance features include a larger capacity float bowl and a higher flowing needle valve assembly to accommodate extended full throttle operation.The Mikuni adjustable accelerator pump provides instant throttle response throughout the RPM range. Mikuni HSR42/45s are available in complete bolt-on kits for most Harley-Davidson models.

Mikuni HSR Kit for Harley Order No. 001-635
More HSR Kits

Here's the real racing carburetor for American Big Twin Monster Motors! Mikuni introduces the new HSR48 Flat Slide - the biggest carb ever to the HSR lineup! This smoothbore carburetor offers the highest air flow possible while providing highly accurate fuel metering, more power, and MikuniĻs renowned precision throttle response. A new extended main jet and larger fuel valve assure ample fuel supply for very powerful engines. The HSR48 offers all the same features as the popular HSR42 & 45 Carburetors for Harley Davidson Twins. All HSR carburetors are designed with an 8-roller bearing flat throttle slide assembly that allows an unobstructed venturi at full throttle to flow more air, while it carburetes more precisely at all throttle settings. Mikuni's roller bearing throttle slide offers smoother throttle control and allows the use of a lighter throttle return spring for reduced throttle effort. And the Mikuni adjustable accelerator pump provides instant throttle response in any riding or performance application. While a high capacity float bowl prevents fuel starvation even under full throttle application. The new HSR48 comes complete with rubbler mounting flange, choke cable, remote idle adjuster and additional jetting.

Mikuni RS Carburetor

Mikuni RS Carburetor
The Mikuni RS Series Carburetors were designed and built in response to the needs of the world's top motorcycle road race and drag race teams. They required carburetors which would satisfy the precise fuel metering demands and high flow volume required by highly modified race engines. And yet, also provide the smooth, controllable throttle response that is needed by any rider pushing his motorcycle to its limits on the race track and under high performance use.

The carburetors need to meter fuel correctly under a wide range of atmospheric conditions and engine tuning modifications while being easily accessible for trackside tuning changes which need to be made quickly.

Designed for in-line four cylinder performance motorcycle applications, the Mikuni RS Series Radial Flat Slide Carburetors offer superior horsepower gains with their maximum flowing smoothbore induction tract and radial flat slide design. An adjustable accelerator pump system helps to provide instant throttle response, particularly in the lower RPM range.

The RS series Carburetors feature a compact design which is 25% lighter than other performance carburetors, offers quick needle jet adjustment, and uses readily available standard Mikuni jets. Carburetors are available in 34, 36, 38, and 40mm bore sizes with different carb spacing for some Suzuki, Kawasaki, and Yamaha motorcycles.

Sudco/Mikuni Vintage Carburetor Kits
Triumph Kit Part No. 001-276

Vintage Carb Kits

Sudco/Mikuni Vintage Carburetor kits come complete and easily to bolt on for each application. Sudco pre-tested kits eliminate the problems of jetting specifications because all Carburetor Performance Kits are pre-jetted and include extra jets for fine tuning.

Box that old Amal or Bing! For improved starting, reliability and increased performance a Sudco/Mikuni Vintage Carburetor Kit is the first or only modification you'll want to make to your vintage bike.

Pre-jetted carburetors available for:
Vintage Racing Motorcycles (AJS, BSA, Bultaco, Can Am, CZ/Jawa, Ducati, Honda, Husky, Kawasaki, KTM, Maico, Matchless, Moto Guzzi, Norton, Rickman, Rotax, Suzuki, Triumph, Vincent HRD, Yamaha, etc.)

VM Round Slide Carbs
VM Series Carburetors

These are the most popular performance single carburetors in the sport of motorcycling. Mikuni's VM Series round slide single carburetors have proven themselves as the performance standard for use in any single cylinder motorcycle and ATV application for motocross, enduro and trail riding, to flat track racing and road racing on both 2-stroke and 4-stroke engines.

Performance features for the VM series carburetors include a large selection of bore sizes for fuel mixture flow to match any engine modifications. A wide range of tuning components to allow precise fuel mixture metering in any application, at any throttle setting, and under any riding condition.
  • VM Roundslide Singles:

  • Sudco Special Set Mikuni VM Roundslide and TM Flatslide Singles

    Sudco can "Special Set" any Mikuni Carburetor for your particular application. Below is the information you will need to provide our Carburetor Techs so they can provide you with the correct carburetor and jetting, when you are purchasing a carburetor.
    1. Carburetor Size (mm)
    2. Type of carburetor (Clamp-on, Spigot Mount, Flange Mount, Flat-slide, etc.)
    3. Application (Model, Year, Displacement)
    4. Modifications to motorcycle (Explain)
    5. Type of motorcycle use (Street, Road Race, Drag, Motocross, Enduro, etc.)
    6. Type of fuel used
    7. Climate Conditions (Altitude, etc.)

            Harley Davidson Carburetor Kits (VM Carbs)

    TM Series Flat Valve Carbs
    TM Series Flat Valve Carbs
    Mikuniís original flat valve (flat slide) carburetor, the TM Series Carburetors provide significant performance improvements over older design round slide carburetors. Air flows faster and smoother through the TM Series venturi due to the flat slide configuration and the jet blocks which help create a smoothbore effect. The high velocity of the air flow means a stronger vacuum at the needle jet, providing more precise metering and better throttle response.

  • TM Flatslide Singles:
  •     List of TM Carburetors
        Parts List

    TMX Carburetor for Motocross
    TMX CarbsTMX38-2 Carbs

    Mikuni designed the TMX particularly for 2-stroke engines in motocross, off-road, and ATV racing applications. The TMX features a radial flat slide design, and a lightweight compact body.

    The TMX35 is suggested for 125cc race engines, and the TMX38 for Open class machines. An evolution of the popular Mikuni TMX model, the Mikuni TMS38 offers vastly improved mid-range and top-end performance with precise jetability. Design changes include a TMS flatslide throttle with no cutaway. Instead the slide has a specifically designed internal chamber with two metering orifices. There is no screw-in pilot jet, and the pilot fuel is now metered by the jet needle. Tuning is quicker and more simplified with less components. The installation of an optional special jet needle (The Pro Option Needle Kit) in the TMS allows the main jet to be removed.

    Genuine Mikuni Jets

    Check the Mikuni Jets Page to see which jets your carb uses.

    Go back to top