Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/625324
2016 KTM 690 DUKE FIRST RIDE P76 THAT ENGINE KTM's main objective in creating the new 690 Duke was to bring this en- gine right up to modern day technol- ogy standards and to do that, they had to go through the entire engine. The result is a seven percent power increase to 73 horsepower and a six percent torque increase to 54 lb-ft. "We had to redesign many aspects of the engine," starts lead engine designer Sebastian Faist- auer. "In the cylinder head we added an additional balancer shaft, which is working alongside a completely new crankshaft, conrod and piston. We changed the timing chain to a new silent system; prior to this we were using roller chains but with the new silent system there were two benefits. The first being the system is much smaller, and the second is increased durability." The cylinder head in the new 690 still uses a single camshaft design, but at first glance you'd be forgiven for thinking it's a twin cam due to the balancer shaft at one end. "This design therefore means less weight and less oscillating masses and vibrations, which you instantly feel on the road," said Faistauer. "The intake valves are controlled using DLC (Diamond Like Carbon) coated finger followers and we are using a directly controlled (i.e acting directly off the camshaft) rocker arm on the exhaust valves. We used a lot of our twin-cylinder experience in creating this new intake system." Magnesium was used in the creation of the valve cover, saving a precious few grams, and the resona- tor chamber located in the inlet tract. "With this configuration," states Faistauer, "we can ensure much bet- ter emissions figures and reduced fuel consumption." Down the bottom of the engine, the crankshaft's stroke has been increased 4.5mm to 80mm, bore decreased 3mm to 105mm, and the conrod, pumping up and down a new forged piston, utilizes new plain bear- ings at the big end have been used to minimize friction within the crank drive. "This design is much more compact than before and helps to further reduce the oscillating masses and increase the durability of the system," says Faistauer. "This further enhances ride-ability and a smoother throttle response, and we have man- aged to nearly halve the vibrations from the crank drive over the previ- ous model." The engine utilizes ride-by-wire with twin-spark ignition, part of the reason the Duke is so smooth at the bottom of the rev range. The exhaust has also been changed and is now 2.2 pounds lighter. "In all, we've managed to increase the power range to 9000 rpm and this, combined with the much better ride-ability and decreased vibrations, make this new engine a big improve- ment over the old one," says Faistauer. Totally reworked, the new single- cylinder Duke engine is a very impressive piece of engineering. ful production single ever in the new 690 Duke. The single-cylinder LC4 engine has been a cornerstone of KTM's on-road success. Over 68,000 LC4-powered machines have found homes since 1994, but considering KTM is the only manufacturer who continues to develop large capacity single cylinder road bikes, the fact they have bought an essentially all-new engine to the market is cause for applause. The chassis is largely identical to the previous generation 690 that debuted in 2012, albeit with