Though my ten is 21 months old, with 20000km on the clock, and still in warranty, I made the decision to do the 20k service on my own and void the warranty.
References:
1. Yamaha Service Manual XT660Z TENERE 2008
2. Haynes Service & Repair Manual Yamaha XT660Z Tenere
Jobs performed:
1. Valve clearance adjustment
2. Spark plug change
3. Air filter replacement
4. Engine oil & oil filter change
(Jobs that will be performed later on this year:
5. Lubrication of steering bearings
6. Lubrication of rear suspension relay arm & connecting arm pivoting points)
Spares changed:
Tools used:
(plus 2 torque wrenches)
1.
Firstly, I removed the seat and drained the fuel tank.
2. Then I removed the fuel tank covers. (The bottom left bolt proved pretty stubborn, and it came out together with its threaded housing/sleeve
).

3. So I used some glue…

4. … and stuck it back inside the plastic bracket..


5. I removed the tank bracket, washers and collars…



6. …the front bolts (one on each side)…
