Indmar Marine Spark Plug – Supercharged 575 | Part #597128
Purpose-built for the most powerful engine in the Indmar lineup — this genuine spark plug is the only correct choice for the Supercharged 575 marine engine. The SC 575 operates at significantly higher cylinder pressures and temperatures than any naturally aspirated Indmar engine — demanding a spark plug engineered specifically to handle the extreme conditions of forced induction marine performance.
Compatible with: Indmar Supercharged 575 marine engines fitted to Malibu, Moomba, Supra, and Tige boats. Contact us to verify fitment for your specific model year before ordering.
⚠️ IMPORTANT — Correct Plug for Supercharged 575 Only:
THIS PLUG IS SPECIFICALLY FOR SUPERCHARGED 575 MODELS ONLY.
If your boat is fitted with the naturally aspirated Ford 6.2L engine you must use:
597037-16 – Spark Plug Ford 6.2L CYFS-12FP Set of 16
If you are unsure which engine your boat is fitted with — contact us before ordering.
What makes the Supercharged 575 different?
The Indmar Supercharged 575 is the pinnacle of Indmar marine engine performance — a force inducted powerplant delivering 575 horsepower for the most demanding wake sport applications. The supercharger forces significantly more air into the engine than a naturally aspirated engine can achieve — creating:
- Much higher cylinder pressures at the point of ignition
- Significantly elevated combustion temperatures
- Greater mechanical stress on all ignition components
- More demanding heat range requirements for spark plugs
- Higher voltage requirements for consistent spark across all load conditions
Standard spark plugs simply cannot survive these conditions — the correct plug specification is non-negotiable in a supercharged application.
Why using the wrong plug in the SC 575 is so dangerous:
Installing an incorrect spark plug in the Supercharged 575 risks:
- Pre-ignition and detonation — generating extreme pressure spikes that can destroy pistons, connecting rods, and bearings in seconds
- Plug tip meltdown — incorrect heat range causes the electrode to overheat and act as a glow plug, triggering uncontrolled ignition
- Catastrophic and irreversible engine damage — supercharged engines leave no margin for error with incorrect ignition components
- Complete engine failure at high load — potentially while on the water
The cost of the correct plug set is negligible compared to the cost of rebuilding or replacing a supercharged 575 engine. Always use 597128 — no exceptions, no substitutions.
How often should you replace them?
Given the extreme operating conditions of the Supercharged 575, inspect your spark plugs every season without exception and replace at the manufacturer's recommended interval. High performance supercharged engines accelerate plug wear significantly faster than naturally aspirated engines — never extend service intervals on an SC 575.
Signs your spark plugs need replacing:
- Rough idle or misfiring under boost
- Hard starting especially after winter storage
- Noticeable drop in power or fuel economy
- Engine hesitation or stumbling under acceleration or full boost
- Uneven power delivery or vibration at cruise RPM
- Detonation or knock under load — replace immediately and inspect engine
- Approaching recommended replacement interval
Pro tip: On the Supercharged 575 never ignore abnormal plug readings — what might be a minor issue on a naturally aspirated engine can escalate rapidly under boost pressure. If your plugs are showing anything other than a healthy light tan or grey reading on removal, have your engine inspected before returning it to full power operation.
Pairs perfectly with:
- 525900 – Flame Arrestor Ford 6.2L
- 636127 – Water/Fuel Separator Filter
- 556003 – Fuel Filter EFI All Models
- 685007 – Raw Water Pump Impeller
Features:
- Genuine OEM specification spark plug for Indmar Supercharged 575
- Engineered for forced induction high pressure combustion conditions
- Correct elevated heat range for supercharged operating temperatures
- Superior electrode construction for high voltage supercharged ignition demands
- Designed for sustained high performance marine engine operation
- Not suitable for naturally aspirated Ford 6.2L — use 597037-16
- Direct replacement — no modifications needed
Part Number: 597128
In stock and shipped fast from Australia 🇦🇺
