Malibu The Monsoon 340

Malibu The Monsoon 340(click image to enlarge)

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The Monsoon 340 (340 HP) delivers out of the hole with 397 foot-pounds of torque. This customized version of GM’s Vortec 5.7L is designed specifically for Malibu’s performance hulls. The new Indmar ETX/CAT one-piece tuned exhaust manifolds reduce Monsoon emissions to almost nothing. Add high lift roller cam and free-breathing Vortec heads and this engine equals one of the most powerful, dependable small blocks ever built.
Not available on Sportster.

Developed specifically for Malibu Boats, the Monsoon 340 is a classic small block inboard power package. The Monsoon 340 has as a standard feature Precision Pro Speed Control© (Malibu's privately labeled version of Indmar's ETC-electronic throttle and cruise-system). The Indmar developed system allows the helm throttle control to electronically connect to the engine's ECM. Throttle response is quick and smooth. The Electronic Throttle Control with Cruise feature is a bonus to recreational water-ski and wakeboard families.


New to the 2007 model is the patented one-piece ETX/CAT (Extreme Tuned Exhaust with Catalyst). The most dramatic achievement for boater safety is ETX/CAT's substantial reduction of Carbon Monoxide (CO) gases in all part-throttle operating modes. Neither the California Air Resources Board (CARB) nor the Environmental Protection Agency (EPA) currently regulates CO emissions, but when they do Indmar is ready to meet or surpass those regulations.
There is no measurable engine power loss thanks to ETX/CAT's extreme tuned manifold/catalyst design. The ETX/CAT system is a free breathing, header style performance exhaust manifold, which is designed to incorporate the catalytic converter as a compact assembly.


Certified: 4-Stars Super Ultra-Low Emission by California Air Resources Board 2007.


The Monsoon's brain is Delphi's most advanced water resistant ECM (Electronic Control Module) the MEFI-5 hardware/software system. The MEFI-5 system is custom calibrated by Indmar to provide maximum performance and drive ability. By custom calibrating the ECM to match hull design requirements and the intended boat application this process allows boat and motor to perform as one seamless unit. The three-dimensional system precisely manages fuel, ignition and air. It is programmed to deliver the power skiers' and wake boarders' need, plus the classic turnkey starts, unhesitating dependability and fuel efficiency that only Indmar can deliver.


Outstanding performance and durability, backed by Indmar's exclusive 3-year limited warranty, which includes both fuel and electrical systems.
Note: All Malibu Models are available as Salt Water Specific engines.


Experienced saltwater boaters will be the first to appreciate the extensive list of saltwater-specific details found in the Malibu SS series. All marinized parts are E-coated, an advanced electro-coat dip process that provides optimum protection against corrosion. Unlike paints or powder coating, E-coating completely covers both external and internal surfaces, creating a permanent-paint-to-metal bond. Will not peel. Will not crack. Corrosion will not put a dent in it.
SS Cooling systems are totally closed and corrosion free. Saltwater never enters an SS engine system. It uses only propylene-glycol/water coolant driven by a high-flow pump. Coolant tanks are easily accessible for filling and maintenance and are equipped with sacrificial anodes for extended life.
Each Malibu SS engine is protected by the same three-year limited warranty that backs every OEM installed Malibu engine.


General Specifications

  • Displacement: 5.7L / 350 CID
  • Cylinders: V-8
  • Bore & Stroke: 4.00 x 3.48
  • Compression Ratio: 9.4:1 (High-flow Vortec heads)
  • Exhaust: ETX/CAT (Extreme Tuned Exhaust with Catalyst).
  • Fuel System: Multi-port electric fuel injection (MPFI)
  • ECM: Delphi MEFI-5 hardware/software system that is custom calibrated by Indmar.
  • Ignition: HVS High Voltage Switch Ignition System
  • Fuel Required: Unleaded, 89-octane minimum.
  • Oil Type: Pennzoil Marine (SAE 15W-40), service SJ/CG4
  • Oil Capacity: 5.5 quarts with filter
  • Oil Filter: Pennzoil PZ3
  • Spark Pugs: 41-993 (Platinum Tip)
  • Max. RPM: 5,200



Warranty: Factory-Backed 3 year limited warranty including fuel and electrical.
High Output 90-Amp Alternator: Produces 40 amps at idle.
Heavy-Duty Sealed Wiring Harness:

Exclusive Multi-step Paint Process: To insure maximum protection from rust and corrosion.

Beltless, Crankshaft Driven Seawater Pump: Works better and it lasts longer. Marine-Specific Circulating Water Pump Impeller:
Serpentine Alternator and Circulation Water pump Belt:
Advanced Valve Train: Camshaft with marine-specific performance profile increases low-end torque for hole-shots, while lengthening the flat torque curve for excellent top-end power. Hydraulic roller lifters allow use of fast-action cam lobes to boost power while retaining a quiet idle and reducing friction and wear