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
- 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