At Buckshot Racing #77, we specialize in precision fuel and air injector cleaning, flow testing, and diagnostics for high-performance Mercury Marine and Mercury Racing outboard engines, both 2-stroke and 4-stroke platforms.
 
We focus on legacy EFI engines to modern DFI and air-assisted Optimax systems, ensuring your engine runs clean, powerful, and reliably at every throttle position.
 
We use the industry-leading ASNU Classic GDI Injector Servicing and Flow Testing System, which allows us to simulate real-world fuel pressure conditions, analyze spray patterns, measure flow rates with exact precision, and identify performance issues such as fuel restriction, leaking injectors, or spray imbalance.
 
While this system is capable of testing up to 10 bar (145 psi), we always adhere strictly to OEM pressure specifications for each engine model to prevent damage and ensure accurate results.
 
For 2-stroke Mercury 150, 175, 200 HP, 225 Promax, 225X, XRi, 300X, EFI platforms and Mercury Racing 260 EFI, 280 ROS, 300 Drag, and S3000, fuel injectors are tested and cleaned at their respective operating pressures—typically 39 psi for 260/280 EFI, and 56 psi for 300 Drag and S3000 engines.
 
These engines depend on accurate fueling and balanced injector performance at high RPM, making regular flow testing and ultrasonic cleaning essential for safe, consistent power output.
 
For Optimax DFI systems, like the Mercury 200XS, 300XS, and SST-200, we work with both the fuel injectors and the direct (air-assisted) injectors.
 
These systems operate with separate fuel and air rails, typically running around 90 psi fuel pressure and 80–95 psi air pressure, with a carefully controlled pressure differential that must be maintained to ensure correct fuel atomization and combustion efficiency.
 
Testing Optimax injectors requires a specialized process; we clean and verify the fuel injectors on our bench equipment while observing all pressure limitations. Direct injectors are evaluated for flow, resistance, and potential failure points, and we work within safe tolerances to preserve their performance integrity.
 
Our services also fully support modern Mercury Racing 4-stroke EFI engines, including the 300R, 400R (V10 and L6), 500R, and APX competition series (200, 250, and 360). These engines use multi-port electronic fuel injection (EFI) with typical fuel rail pressures ranging from 58 to 60 psi, regulated electronically by the PCM or with returnless fuel systems.
 
We test these high-flow injectors at both industry-standard pressures (3 bar/43.5 psi) and at OEM-matched levels to ensure accurate real-world performance.
 
Injector cleaning is not just preventative—it directly affects power delivery, throttle response, fuel economy, emissions, and engine longevity. Dirty injectors or uneven spray patterns can lead to lean running conditions, poor starting, misfires, and increased wear on pistons and spark plugs. Ethanol-blended fuels can accelerate injector fouling by causing varnish buildup and corrosion in the fuel system.
 
As part of every service, we replace the injector filter screens, main O-rings, and grommets or sealing components as needed. These parts are essential for maintaining a leak-free, high-pressure seal and are often overlooked during general maintenance.
 
We provide a complete injector maintenance solution: ultrasonic cleaning, flow testing, spray pattern visualization, electrical resistance checks, and pressure-hold leak-down testing—all performed to exacting standards.
 
Every set of injectors we service comes with a comprehensive before-and-after report showing detailed flow data, test pressures, and resistance measurements. This allows you to see exactly how your injectors performed before cleaning, and the improvements we’ve made to restore them to new OEM standards.
 
Whether you're tuning a 300 Drag for competition, restoring a 260 EFI, maintaining a 200XS Optimax, or keeping a 400R or 500R running strong, we have the tools and expertise to handle your injector needs with precision and care.
 
We also provide injector matching, fuel rail cleaning, and specialized Optimax diagnostic services upon request.
 
Simply select the quantity of how many injectors you would like serviced and if you would like drop-off or return shipping. International shipping is available at cost, contact mike@buckshotracing77.com or call +1-714-697-1716
 
Send us your injectors with your return address/phone:
 
Buckshot Racing 77 LLC
Attn: Mike Hill
6350 229th St E
Bradenton, Florida 34211 USA
 
We get it done fast! 2-3 business day turn-a-round time is typical.
 
We have thousands of hours of experience with fuel and air injectors out of EFI and Optimax 2-Stroke Outboards including but not limited to OEM part numbers 1871518715T, 988181, 98818, 8M019227, 883078A05, 8M0065916, 884595A01, 8M6001744, 804528877, 826892123, 280150036, 8M0192275