O.S. SPEED B2103 TYPE R (NSK 307 D eesmine upgrade laager)

This is the OS B2103 Type R engine. This 5-port long-stroke engine offers great power at medium-high speeds. The crankcase, the crankcase cap and the carburetor feature a new design. The new DLC-coated crankshaft has two tungsten counterweights for smooth rotation and better balancing. It shares the same new features as the Type S engine except the cylinder and the cooling head which has a standard round shape.

• The long-stroke off-road engine put a high value on beasty power in mid-high speed range.
• The crankcase, carburetor, cover plate, crankshaft and inner head are designed new.
• All the parts are interchangeable to those of TYPE S’s.
• A newly designed 5-port cylinder & piston set (5 scavenging port+ 3 exhaust port)
• A standard round type outer head
• A newly designed 22E carburetor for producing high power

Technical specifications:

• displacement 3.49cc
• bore 16.27mm
• stroke 16.80mm
• rpm 4000-42000 rpm
• max output 2.64hp/34000 rpm
• weight 354gr
• exhaust T2100SC
• port 5-port