The Outboard Carburetor Jet Drill Bit Kit from Buckshot Racing #77 is a quality-grade tuning toolset designed for legacy Mercury 2-stroke V6 carbureted outboards, including 2.0L, 2.4L, and 2.5L Mercury engines.
 
Built for performance boaters, drag racers, offshore racers, lake racers, and marine mechanics, this kit enables accurate resizing of WH, WMH, and WMV carburetor main jets, as well as WH idle jets, to improve fuel delivery, throttle response, acceleration, and RPM performance.
 
This kit is commonly used on Mercury Carb 245 HP, XR2, XR4, XR6, and other Mercury V6 outboards equipped with WH, WMV, and WMH carburetors.
 
Proper jet sizing is critical on high-performance 2-stroke Mercury engines. Small fuel delivery changes can significantly affect air/fuel ratio, exhaust temperature, piston cooling, idle quality, throttle response, and top-end RPM. Precision fuel calibration helps improve both engine reliability and overall performance.
 
The Kit allows tuners to enlarge jets in small, controlled increments for more accurate and repeatable tuning results. It is especially useful on modified Mercury V6 engines equipped with increased compression, reed upgrades, lightweight flywheels, exhaust modifications, timing changes, velocity stacks, or race fuel setups.
 
WH idle jet tuning improves idle quality, off-idle acceleration, throttle crispness, and transition fuel delivery. WMV and WMH main jet calibration is critical during sustained high-RPM operation, where proper fuel delivery protects pistons and maintains engine durability.
 
Each drill bit is precision-ground from durable high-speed steel for long service life and consistent sizing accuracy. Every bit is clearly marked for quick identification in the case.
 
Common Mercury Carburetor Applications
 
This kit is commonly used on Mercury V6 carbureted engines equipped with WH, WMV, and WMH carburetors found on horizontal front 2.4L engines, vertical reed 2.5L engines, Bridgeport engines, Carb 245 HP setups, modified fishing motors, lake race boats, river race boats, and offshore performance applications.
 
Why Proper Jetting Matters
 
Proper jetting directly affects engine safety and performance. Lean fuel mixtures can create excessive heat and increase the risk of piston damage or detonation, while rich mixtures can reduce throttle response, lower RPM, and foul spark plugs.
 
Precision jet sizing helps improve acceleration, throttle response, idle quality, fuel delivery consistency, and top-end performance while maintaining safer air/fuel ratios under load.
 
Helpful Carburetor Tuning Tips
 
Successful carburetor tuning requires careful testing and accurate adjustments. Most Mercury tuners begin with richer fuel settings and gradually reduce fuel flow while monitoring spark plug readings, engine temperature, piston wash, and RPM consistency.
 
Weather conditions, humidity, elevation, water temperature, and fuel quality can all affect carburetor calibration and may require seasonal jetting adjustments.
When resizing jets, drill slowly, maintain alignment, and thoroughly clean the jets afterward to remove burrs or debris before installation.
 
Included Jet Drill Bit Sizes & Mercury Main Jet Part Numbers
 
Jet Size
Drill Bit Number
Decimal Size
Mercury Part Number
100 Jet
#39
0.0995"
1395-815002100
98 Jet
#40
0.0980"
1395-81500298
96 Jet
#41
0.0960"
1395-81500296
94 Jet
#42
0.0935"
1395-81500294
89 Jet
#43
0.0890"
1395-81500289
86 Jet
#44
0.0860"
1395-81500286
82 Jet
#45
0.0820"
1395-81500282
81 Jet
#46
0.0810"
1395-81500281
79 Jet
#47
0.0785"
1395-81500279
76 Jet
#48
0.0760"
1395-81500276
73 Jet
#49
0.0730"
1395-81500273
70 Jet
#50
0.0700"
1395-81500270
67 Jet
#51
0.0670"
1395-81500267
64 Jet
#52
0.0635"
1395-81500264
60 Jet
#53
0.0595"
1395-81500260
55 Jet
#54
0.0550"
1395-81500255
52 Jet
#55
0.0520"
1395-81500252
 
Whether you're tuning an XR6 lake motor, a Carb 245 HP race setup, or WH idle jets for sharper acceleration, the Buckshot Racing #77 Jet Drill Bit Kit delivers the precision tuners trust.