A new engine, that debuted in the Husqvarna 701 SM in 2016, with a new parallel-mounted balancer shaft, a new bore/stroke ratio of 105 x 80mm (previously 102 x 84.5mm) and a slightly higher compression ratio (12.7:1 versus 12.5:1 before). Engine performance was up to 72hp (or 74, depending on the sources) from 65-66hp. Torque also rose from 68 to 73N/m.
They dropped the Kokusan ignition in favour of the Keihin RBW.
Weight rose from about 140kg (dry) to about 147kg (dry).
Fuel tank grew a bit in size (a couple of litres or thereabouts).
Suspension was also modified, with the bike sitting lower and the suspension travel being reduced.
Electronics: lots. Cornering ABS with Supermoto mode, two engine modes, traction control, engine braking regulation and quickshifter (which I think is optional).
From 2019 onwards, I think the changes are really into details and visuals. There might be some other things, but those came to mind. The difference while riding isn't huge though.
08-11 654cc single spark original gangster SMC
12-13 690cc single spark ( best engine, really torquey ) SMC-R
14-17 690cc twin spark model, feels a bit flatter than the previous model, not as raw or punchy, still great though
18-On - Twin balancer shaft added, smooth as silk now, power hike
Euro 5 - ABS can not be turned off completely
Mode 2 now activates Supermoto ABS (front only)
Seat pan has changed, 2019/20 seats do not fit
Seat release is now under the fuel filler cap.
Larger ECU, space between battery and fuses has plastic grid where a PCV would go.
Mono block front caliper
Diagnostic plug has changed.
New dash with gear indicator and revs.
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