I'll add my $.02 to the discussion here. There is a TON of great info in this thread and the thetenerist site -- many thanks to all those that have done this job before and posted up their experience.
First off, this was everything it was promised to be -- a major PITA. In fact, I've been apprehensive about this job before I even bought a Tenere. I read about what a pain it was when doing research on the bike and made a mental note... so I've had two years to let this to fester in the back of my mind.
I consider myself a relatively competent mechanic, I've done valve check/adj on multiple bikes and cars over the years and do all my own maintenance, but this really pushed my mechanical aptitude this weekend. Looking back, it's really not that bad (easy to say now) but there are so many little things that can make the job a lot easier, and a lot of little things to overlook that can turn it into a complete disaster.
Things I did wrong...
- Removing the valve cover: I did not remove the brackets holding the hard brake lines in place that run back to the ABS unit, I just completely overlooked that step in the shop manual and in this thread. When reinstalling I undid everything and the valve cover went back on so much easier. If the cover isn't coming out by pulling it straight out (you don't need to twist/rotate it), stop and find what's in your way. It's really not that bad with the wiring on right side zip tied out of the way and those brake lines on the left zip tied out of the way.
- Marking the cams/chain: More marks don't necessarily mean better, at least in my case. I made multiple (and not entirely clear) marks on my exhaust cam and on reassembly didn't notice that I had the wrong marks lined up until after I had torqued everything back down, reset the CCT and tried to turn the motor by hand. I wasted a lot of time having to go back and repeat removal of the CCT, zip-tieing things, removal of cam caps, etc.
Things I did right, mostly thanks to the tips on this site...
- Resetting the CCT with a vice helps a ton, I'm not sure how you'd do it without one. Note that the CCT plunger/piston has to spin in the body of the unit. I was twisting the housing and didn't realize why it wasn't plunging back in until I noticed that the piston was spinning as well. An old inner-tube on the vice fixed that problem.
- Spin the motor by hand once you have it reassembled. Multiple times. My cam installation error would have been absolutely catastrophic had I buttoned everything up and hit the start button.
- If you do have to pull the cams, taking the time to mark the other side of the sprocket with a file or something (you know, the side you can actually see) is a great tip.
- Pressurizing the crank case via the breather to make sure your valve cover gasket is seated correct is a nice tip and piece of mind since you can't see the perimeter of the entire cover very well.
- Mark connectors/hoses/cables. There's a LOT of spaghetti down there once you have everything disconnected... I marked everything that looked like it'd be even remotely confusing later with blue painter's tape and a marker (top throttle cable / green electrical connector / etc).
Other general advice... don't skip it. I'm a relatively tame rider, I don't know that I've ever hit the rev limiter on this bike... almost all of my miles (26k miles) are highway cruising and commuting via backroads. I was
not expecting to have to swap shims on this thing with my riding style but every exhaust valve was tight, between .19mm-.21mm (spec is .22-.28mm). The earlier talk about them being set at the tight end of spec from the factory I would bet is right. Now that I have them set out to the loose end of spec I don't expect to ever have to swap another shim (knock on wood). Intake clearances were all fine towards the middle of spec.
So long story long, it's a huge PITA but completely doable job. I probably spent 15 hours on it this weekend but now that I know what I know I think 7-8 hours would be a reasonable estimate. If you don't have to adjust the clearances I'd think 4ish hours to get in there and get back out.
Good luck!
trey