Marine Carburetor Jetting for Altitude/Performance
Peak Power.
Any Elevation.
Factory carburetors are tuned for sea-level compromises. Whether you are towing your boat to high-altitude lakes or chasing maximum wide-open-throttle performance at the coast, we recalibrate your jets and metering rods for the perfect stoichiometric ratio.
High-Altitude Leaning
Taking your boat to Lake Tahoe or Big Bear? Thin air causes sea-level carburetors to run dangerously rich, washing engine cylinders and destroying power. We calculate density altitude and downsize your jets for crisp, clean combustion in the mountains.
WOT Performance Tuning
Engine sputtering or falling flat at Wide Open Throttle? We read your spark plugs to analyze the fuel burn. We upsize main jets to prevent dangerous lean-out detonation and extract every horsepower from your top end.
Transition Circuit Sync
It is not just about the main jets. We tune the transition circuits, swapping power valves, accelerator pump nozzles, and metering rods so your boat accelerates smoothly "out of the hole" without hesitation or bogging.
The Calibration Process.
Math meets mechanics.
Baseline Diagnostic
We perform a baseline run or "plug chop" to analyze the current air/fuel mixture. White, blistered plugs indicate a lean condition, while black, sooty plugs mean you're running rich.
Altitude & Flow Math
We calculate the target jet size based on your primary boating elevation. The general rule is a 2% reduction in fuel area for every 1,500 feet above sea level, adjusted for your specific engine load.
Precision Swapping
We carefully drop the carburetor fuel bowls and extract the brass main jets, power valves, or metering rods, replacing them with precision-machined Holley, Edelbrock, or Rochester components.
Verification Trial
The engine is run under load to verify the changes. We ensure smooth idle vacuum, instantaneous throttle response, and safe, powerful wide-open-throttle RPMs.
Tuning Components.
Precision brass & valving.
Technical Specs.
Calibration standards.
Common Questions
Why does my boat lack power and smoke at high altitude lakes?
At 6,000+ feet, the air is thin (less oxygen). Your carburetor is still dumping sea-level amounts of fuel, causing a heavily "rich" condition. Rejetting reduces the fuel flow to match the thin air, restoring power and eliminating black smoke.
Can running too lean damage my engine?
Yes. If your jets are too small (too lean) at sea level, the combustion chamber burns much hotter. This lean-burn detonation can melt pistons, burn exhaust valves, and blow head gaskets.
| Manufacturer | Breeze Marine Boat Service |
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