New Products

High-quality radiator caps designed to increase pressure in the cooling system, which raises the coolant's boiling point for improved performance. Features high-temperature silicone seals. Includes high-temperature metal film warning decal and adhesive. For competition use on most Honda, Kawasaki, Suzuki and Yamaha models.

Kit includes: black powdercoated cylinder, 54 mm forged piston, ring, pin, and gasket kit. Compression ratio of 11.38 to 1. Designed for use with optional Performance Camshaft kit, PART #0925-1511. Kit includes: black powdercoated cylinder, 54 mm forged piston, ring, pin, and gasket kit. Compression ratio of 11.38 to 1. Designed for use with...

Performance engine upgrade components including a 170cc Big Bore kit for Honda Grom and Monkey. The kit includes a ceramic coated cylinder, 61 mm forged piston, rings, pin, gasket kit and banjo bolts with a compression ratio of 11.5 to 1. An optional camshaft kit can be used with a stock engine but delivers improved results with Big Bore kits.

An ideal engine part to complete KOSO's Big Bore kit. The unique four-valve design increases air flow and performance to provide more power and torque. Features a forged piston, stainless steel 24 mm intake valves, and 20 mm exhaust valves.

Increases the oil flow by 40%, helping to prevent engine failure. Keeps the engine lubricated to optimize performance. Recommended for bikes equipped with KOSO Big Bore/4V kits.

Prevents loss of coolant due to overheating, ideal for most water-cooled motorcycles, snowmobiles, and ATVs. Specially designed for hot weather and/or high-altitude riding conditions. Features a compact, versatile, high-density polyethylene bottle with a chemical-resistant rubber cap. The kit includes the 275cc bottle, hose, clamps, mounting ties,...

Replacement seal rings for PC Racing Flo Stainless Steel oil filters.

Embedded magnet helps keep bolt in place. Pre-drilled holes make for easy installation of safety wires. Available in black. Embedded magnet helps keep bolt in place. Pre-drilled holes make for easy installation of safety wires. Available in black.

Clamp down engine hoses while adding a dash of color to your engine. Easy install mounting and holding coolant lines and wire looms. Does not require disconnecting coolant hoses for installation. No drilling required; utilizes pre-existing bolt holes. Made of aluminum. Clamp down engine hoses while adding a dash of color to your engine. Easy...

Attracts and holds ferrous metal particles floating in your engine. Also acts as an early-warning diagnostic tool to help indicate any potential problems that may need servicing.

A comprehensive range of EBC clutch kits, springs, and components for various motorcycle applications, from street and sport to full race use. Includes cork-based standard kits (CK), carbon-fiber kits (CKF), heavy-duty kits (DRC), and aramid fiber race/sport kits (SRC, SRK), as well as stiffer clutch spring sets (CSK) and OEM replacement diaphragm...

Fixes the hard-to-reach OEM dipstick and simplifies important oil maintenance. Made from high-quality aluminum with Buna-N-Rubber o-rings, it is easy to install and measures 5.4" in total height. Fixes the hard-to-reach OEM dipstick and simplifies important oil maintenance. Made from high-quality aluminum with Buna-N-Rubber o-rings, it is easy to...

Studs are heat-treated 180,000 psi aircraft alloy steel. Nuts are machined from billet high-tensile steel and heat-treated. Both nut and stud have rolled threads for the strongest threads possible. Black oxide treated for corrosion resistance. Made in the U.S.A. Studs are heat-treated 180,000 psi aircraft alloy steel. Nuts are machined from billet...

Designed to out-perform and outlast factory valve springs. These kits are progressively wound using Kobe super-clean, chrome silicon-based wire that is heat-treated and shot-peened. They feature tight-tolerance retainers and hardened steel base washers to control lateral movement. Kits use OEM-style valve keys (sold separately). Made in the U.S.A.

High-performance valvetrain components designed to last longer than OEM. White Diamond® valves are one-piece forgings with hard chrome stems. Inconel® 751 exhaust valves are for extreme applications. Valve guides are made of C630 nickel-aluminum bronze. Sold individually. Made in the U.S.A.

All valve seals are made of 100% solid Viton® for long life. Sold individually. Made in the U.S.A. All valve seals are made of 100% solid Viton® for long life. Sold individually. Made in the U.S.A.

Long lasting OEM replacement cam chain tensioners. Arm made of 6061 aluminum, wheel made of structured steel. Compatible with stock engine configuration but recommended for use with KOSO Big Bore/4V kits (sold separately).

CNC machined for added strength over stock. Adds durability and stability to the clutch during installation and while shifting gears at high speed.

240° performance camshaft offers the best results at high rpm. Formulated to increase output with a stock engine but offers best results when combined with 170cc big bore kits. Longer expected durability vs. stock parts. Duration at 1 mm In: 260, Ex: 265. Valve lift In: 8.5 mm, Ex: 8.5 mm. Running clearance In: 0.10 mm, Ex: 0.17 mm. 240°...

Low-cost alternative to complete case covers. Offers protection against engine oil spillage in case of a crash. CNC machined from billet aluminum.

Perfect for making your own gaskets including transmission covers, timing covers, oil pans and intake. Delivers excellent sealing properties. Features fiber gasket material recommended for all oil applications.

Heavy-duty spring kit contains six powdercoated springs, stainless steel screws and a choice of anodized spring cups; does not increase lever effort. Made in the U.S.A. Heavy-duty spring kit contains six powdercoated springs, stainless steel screws and a choice of anodized spring cups; does not increase lever effort. Made in the U.S.A.

A comprehensive range of high-performance gaskets and gasket kits for various motorcycle makes and models, including head, base, clutch cover, exhaust, stator cover, and lower end kits.

Kit PART #0925-0010 includes three 7.48 mm OD shims in each size from 1.20 mm to 3.50 mm in 0.05 mm increments. Refills sold to dealer in 5 pk.; sold ea. to consumer.

Includes all applicable O-rings, springs, washers and gaskets required for all cylinders.