01. Engine & Exhaust

Engine
The LC4 690 cc single-cylinder engine combines powerful acceleration from the very lowest revs with an outstanding free-revving nature and refined engine running. Another big plus is besides the engine being extremely economical with fuel it also has long service intervals of 10,000 km, keeping running costs low.


Cylinder head
A lightweight, compact cylinder head contains four valves and a single camshaft placed over the intake valves, and a secondary balancer shaft driven by the timing chain. The intake valves are actuated by finger followers and the exhaust valves by a rocker arm.

Resonator chamber
A resonator chamber balances out pulses in the intake tract and makes the throttle response smoother with reduced vibrations.

Balancer shaft
Twin balancer shafts, one in front of the crankshaft and the other in the cylinder head reduce vibration, which ensures a smoother ride.

Piston
The lightweight and durable forged piston is designed to reduce reciprocating mass, and therefore improve engine response.
Conrods
Plain bearings are used in the conrod to ensure a reduced reciprocating mass, which helps the engine run smoother and therefore enhances its lively character.

PASC clutch
The PASC (Power Assist Clutch) ensures the rider needs minimal input to operate it, due to less engine torque transferring to the clutch plates. The slipper clutch prevents rear wheel lock-up under aggressive downshifting, which reduces destabilising rear wheel chatter on the tarmac when braking sharply or decelerating into turns.


Gearbox
The smooth 6-speed gearbox with Quickshifter + allows quicker clutchless up and downshifts when you’re on the gas in and out of turns. This not only enables the rider to be more in control of the motorcycle by keeping a full grip of the handlebars, but also improves rear-wheel traction.


Ride-by-wire
The 690 SMC R is equipped a ride-by-wire system, which processes throttle twist grip movements with the help of electronic sensors and activates the throttle valves to control throttle action. This significantly improves the response, giving the rider better throttle control of the potent single-cylinder and a smoother ride.

Crankcase

Exhaust
The exhaust system is made using high-quality stainless steel. It’s routed as close as possible to the bike to help with the slim profile.


Airbox
Accessing the airfilter for maintenance is easy thanks to the airbox being located under the seat. This makes servicing the bike simple, and strees free, at the end of a long day’s ride.
