Boyesen Supercooler Water Pump Kit
MSRP: $199.95
$159.96
Exact Fitment Guarantee
The Boyesen Supercooler Water Pump Kit is a championship-winning thermal management upgrade engineered to replace restrictive OEM water pump covers and stamped impellers on modern four-stroke and two-stroke motocross engines. High-revving competition four-strokes generate massive thermal loads; under heavy race conditions or tight mud tracks, factory water pumps create severe hydrodynamic cavitation—microscopic vapor bubbles that collapse and prevent coolant from contacting the cylinder walls, leading to rapid boiling, horsepower loss from thermal expansion, and head gasket failure.
The Supercooler kit resolves this through patented hydrodynamic design. The water pump cover is precision cast from aerospace-grade aluminum, featuring an enlarged internal intake cavity with smoothly contoured water passages that eliminate the sharp 90-degree internal bends found in OEM covers. Paired with Boyesen's investment-cast aluminum high-flow impeller with curved, hydro-dynamically shaped vanes, the Supercooler increases coolant flow rate by up to 25-30% while completely eliminating cavitation. By moving coolant through the engine faster and more efficiently, the Supercooler lowers engine operating temperatures by 10 to 15 degrees Fahrenheit, preserving peak engine horsepower and preventing boil-overs during long motos.
- Cover Material: Precision investment cast aluminum alloy
- Impeller: Hydrodynamically shaped high-flow aluminum nautilus impeller
- Cooling Performance: Increases coolant flow volume by up to 25-30%
- Thermal Reduction: Lowers peak engine operating temperature by 10°F to 15°F
- Sealing: High-grade nitrile case gasket and stainless steel mounting hardware included
### Step-by-Step Installation & Safety Protocols Installation requires draining the engine coolant completely into a clean container. Remove the stock water pump cover bolts, gently tapping the cover with a plastic mallet to break the gasket seal. Unscrew the factory impeller from the water pump shaft (note whether your model utilizes standard right-hand or reverse left-hand threads). Clean the pump cavity and inspect the mechanical water pump shaft seal for leaks. Thread the Boyesen high-flow impeller onto the shaft, torquing to 6-8 Nm with blue Loctite. Place the supplied Boyesen gasket onto the engine case, install the Supercooler cover, and torque the cover bolts in sequence to 8-10 Nm. Refill the cooling system with high-grade motorcycle coolant, burp the cooling system of air pockets, and check for leaks.
### Maintenance & Coolant Care Maintenance consists of routine coolant flushes per your factory manual intervals and checking the weep hole for seal leakage.
Frequently Asked Questions
Q: How does lowering engine temperature help maintain horsepower?
A: When an engine overheats, cylinder and piston tolerances swell, oil viscosity thins, and the engine ECU often retards ignition timing to prevent detonation, causing a noticeable loss of horsepower. The Supercooler maintains stable, optimal thermal conditions.
Q: Can I run the Supercooler with standard engine coolant?
A: Yes. The Supercooler works effectively with standard ethylene glycol, propylene glycol, and waterless racing coolants.
Q: Does the Supercooler cover stick out further than the stock cover?
A: The Supercooler cover is engineered with a low-profile exterior that easily clears standard aftermarket skid plates and brake pedals while optimizing internal volume.
Q: Can a worn water pump seal cause coolant to enter the engine oil?
A: Yes. If the internal mechanical water pump seal fails, coolant can weep into the transmission or engine oil; always inspect the seal when replacing the water pump impeller.