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Demon Carburetion Speed Demon 650CFM 650CFM-MS-DL Carburetor
Demon Carburetion Speed Demon 650CFM 650CFM-MS-DL Carburetor

Demon Carburetion Speed Demon 650CFM 650CFM-MS-DL Carburetor

4-Barrel Carburetor Barrels, Gasoline Fuel Type, Electric Choke Type, 650 CFM CFM, Polished

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Demon Carburetion Speed Demon 650CFM 650CFM-MS-DL Carburetor
Demon Carburetion Speed Demon 650CFM 650CFM-MS-DL Carburetor
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We estimate this item will ship on or before November 20th.
Part # 425SPD650MS
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Important Messages:

  • This item ships directly from the manufacturer. It may take an additional 2 business days for Demon Carburetion to ship this item.
  • Get FREE shipping when your order includes this item and exceeds $99! Ground shipping only in the contiguous US.
  • This item ships via Ground Shipping only. Expedited and Air shipping options are not available.


Carburetor Barrels:
Fuel Type:
Choke Type:
650 CFM
CFM Range:
600-699 CFM
Carburetor Flange Type:
4-Barrel Square Bore
Material Type:
Secondary Type:
Bolt Hole Pattern:
5.160" x 5.625"


The next generation of Speed Demon™ carburetors have arrived. The new aluminum Speed Demon™ series is the most formidable performance street carburetor available today and it’s 40% lighter than the original. It features the most advanced design manufacturing processes that provides street enthusiasts with racing carburetor technology in a very drivable package. The Speed Demon™ line offers a wide range of sizes with vacuum and mechanical secondary designs. Across the range of sizes, from 650 cfm to 850 cfm, the Speed Demons deliver balanced, high–velocity airflow and exceptional fuel metering capacity to match the fuel requirements most street engines. A Speed Demon™ carburetor is ideal for muscle cars, stock rebuilds, mild performance applications, and crate motors. They are designed for mild engines from 302-427 cid with cam profiles between 220 and 240 degrees duration at 0.050".


  • All aluminum polished construction with billet metering blocks and base plate (Now 40% lighter than the original Demons!)
  • Fuel bowls and main body have been redesigned for a sleeker, more stylish appearance
  • Completely re-engineered and re-calibrated for better drivability and full throttle performance
  • Re-designed throttle lever with integrated Ford A/T, 700-R4, and Chrysler kick down options
  • Fuel bowls now have dual threaded inlets on each side, dual sight glass windows, and internal baffling for improved fuel slosh control
  • Changeable idle, high-speed air bleeds & power valve restrictions for precise tuning
  • Billet Baseplate with Idle-Eze™ allows precision fine tuning of the idle speed resulting in a smoother transition from off-idle
  • New simple part numbering system: Start with SPD (Speed Demon) Add the carburetor cfm size (650, 750, or 850) and then add the model suffix; MS (Mechanical Secondaries); VS (Vacuum Secondaries); AN (Annular Discharge Boosters)


  • Barrels 4
  • Billet Color Shiny
  • Booster Down Leg
  • Brand Demon
  • CFM 650
  • Choke Electric
  • Circuit 2
  • Emission Code 3
  • Finish Shiny
  • Fuel Gasoline
  • Fuel Inlet Dual
  • Fuel System Carbureted
  • High Speed Air Bleed 31
  • Idle Air Bleed Size 70
  • Material Aluminum
  • Model Demon 4150 Mechanical Secondary
  • Primary Main Jet 70
  • Primary Power Valve 6.5
  • Primary Pump Nozzle Size 31;31
  • Product Type Carburetor
  • Secondaries Mechanical
  • Secondary Main Jet 76
  • Supercharged Application No
  • Throttle Bore 1.688 inch
  • Part Number SPD-650-MS
Some parts are not legal for use in California or other states with similar laws/regulations

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