2026 Beta 350 RX Kingpin

2026 Beta 350 RX Kingpin

The Kingpin has arrived. For 2026 Beta went big, adding an all-new 350cc two-stroke to the RX motocross line — a purpose-built big-bore that replaces the 300 RX and lines up alongside the new 250 RX and the MXGP-proven 450 RX. Beta's engineers spent a couple of years getting the power character just right, with one goal: open-class two-stroke muscle delivered with Beta's trademark RideAbility — a bike that's easier to ride fast, not just faster.

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All-New 350 Engine

This isn't a bored-out 300 — it's a completely new, purpose-built engine designed around linear, usable big-bore power. The highlights:

• 351.7cc big-bore two-stroke — new engine cases with a 78 x 73.6mm bore and stroke and a longer crankshaft, built to deliver the torque and horsepower only a big-bore 2-stroke can provide.
• Twin-plug cylinder head — dual spark plugs for cleaner, more complete combustion. The result is a wider, more linear powerband with big torque down low and the over-rev to keep pulling.
• Counter balancer — smooths out vibration so the big single stays comfortable through long motos.
• 5-speed gearbox with 14/47 final gearing — ratios and final drive tuned to put the torque to the ground on a wide range of track conditions.
• Keihin PWK 38mm carburetor with pre-mix lubrication and Beta's BPV (Beta Progressive Valve) exhaust valve system.
• Electric start is standard, with a backup kick starter available as an option.
• Wet diaphragm-style clutch.

MX Chassis & Components

• KYB AOS 48mm closed-cartridge fork — adjustable compression and rebound damping, 12.0 in. of travel.
• KYB 50mm rear shock — adjustable rebound plus high- and low-speed compression damping, 11.8 in. of travel.
• Molybdenum steel double-cradle frame with quick air-filter access.
• Nissin brakes — 260mm floating front rotor with dual-piston caliper, 240mm rear rotor.
• 21" front / 19" rear wheels with Dunlop Geomax MX34 tires (80/100-21 front, 120/80-19 rear).
• O-ring chain final drive.

Specifications

Questions about this bike? Call Vamoose Gear Powersports at (970) 765-8950 or stop by 1912 S Townsend Ave in Montrose, CO.