13 Loosen the cylinder head...
13 Loosen the cylinder head nuts in a cross pattern. Work a bit at a time and be careful with the two that are inside the engine. You definitely don't want to lose a nut or washer down inside the engine cases.
14 Remove the cam gear shaft...
14 Remove the cam gear shaft cover from the left side of the cylinder head. It holds the shaft in place and keeps it from spinning. Gently work out the shaft. Try not to mark it up in the process.
15 When the shaft is out...
15 When the shaft is out of the gear, it will drop down so it can be removed. Be careful not to lose these bearings as the gear lifts out. Inspect the shaft and bearings for wear and damage.
16 Lift the head straight...
16 Lift the head straight up. It will have to get extremely close to the frame backbone before it will clear the studs. Watch for coolant hoses messing up the lift off. The chain is allowed to settle gently into the cases.
17 The cylinder will resist...
17 The cylinder will resist being lifted. This water junction is a tight fit with the back of the engine sidecase. We loosened the bolts in the water-pump area to ease this connection and make the cylinder come away easier.
18 This was the only sign...
18 This was the only sign of use that the engine showed. The standard gap is 0.2mm and ours had 0.75mm. The piston/cylinder looked fine, so we changed rings, gaskets and O-rings.
19 Two O-rings in the case...
19 Two O-rings in the case opening and another around the cam-chain opening act as a base gasket. Use grease on the cylinder O-rings to hold them in place and allow the cylinder to slide past without unseating them.
20 Getting the rings into...
20 Getting the rings into the oiled cylinder is a pain. KTM removes the piston and uses a ring compressor to get it started in the cylinder; both go onto the engine together, and you only have one circlip to deal with.
21 The junction to the water...
21 The junction to the water pump got a fresh O-ring and coat of silicone. The pump/cylinder junction is a tight one. The engine got a new head gasket, and it was installed dry.
22 Locate the cam gear in...
22 Locate the cam gear in the chain with the bearings inside and ease the shaft through. Needle bearings can crush, so don't force it. The cover locates the shaft, so the flats must be vertical.
23 The engine is locked at...
23 The engine is locked at TDC, so line up all the paint marks and install the cam carriers. Torque the bolts (cross pattern) to 14 Newton-meters. There's no clearance for a 3/8 drive torque wrench.
24 Compress the cam-chain...
24 Compress the cam-chain tensioner until the inner plunger extends 4mm, then screw it back in with the outer cover only. Push the internal plunger with a blunt tool inserted through the inspection hole. You should hear it release. Install the outer nut.
25 Install the cover over...
25 Install the cover over the end of the cam gear shaft. Make sure the shaft is aligned with the dimple on the cover. Did you remember the nut on the little stud below the cover?
26 Use great care with the...
26 Use great care with the cam cover bolts. They thread into the cam carriers, so stripping them will be an expensive pain in the rear. The bolts are torqued to only 10 Newton-meters-and that's a bit past finger-tight.
It's time to button up everything that was removed to access the engine. Make absolutely sure to remove the bolt locking the crankshaft! Replace it with the original Allen bolt and copper washer. Take special care with the coolant hoses and clamps, the throttle cable routing and the carburetor clamps and vent hoses. Fill the coolant and put oil in the engine. Start the engine and look for any leaks. If everything looks good, break in the bike for a couple of heat cycles, then go ride.