I've searched around an surely the answer is here somewhere, but......

What are signs that the valves are getting out of adjustment and need shims?

Any damage that will occur if pushed to far?

About what is the expected cost in 2022 for a shop to do this work?

About how much time for someone reasonably mechanically capable to do this if they have never done it before ?

I have a 2007 that has about 8700 miles on it. Runs good as far as I can tell. I've only had it for about 1700 miles and the history is not known.
Should I worry about this or just ride the thing. ???

 

If you have the skill, it is intimidating, but not hard to do the work. It seem like a hard job, but not too bad. Tear down to the point where you have the cam cover off. Turn the crank until the engine is at TDC with both cams off of the valves (clearance) and the marks on the cam sprockets align with the head surface (if the MCM was done the marks will be 2 teeth off, intake counterclockwise and exhaust clockwise) . Easy enough to do, Check clearances and write them down if you need to do some adjustment, you will need the information when figuring if you need a smaller or larger shim. I'd say mark E1, E2 and I1, I2 with 1 closest to the sprockets, simple but works. Pull the cam chain tensioner, take off the cam cap, I tucked some shop rags in around the various passages where I could drop stuff.

I forget if it was hard or easy to pull the shim retainer caps off the valves, but not bad, a good strong magnet might work to help. The shims were stuck in the caps for me, so I just popped them loose (stuck by surface tension and oil) noted which was in which valve so I got things right. You need at least a caliper, but a 0-1 micrometer is better. Clean the shims measure them and note the thickness, because you will either go thinner if clearance is tight, or thicker if clearance is loose. I just ordered the shims I needed rather than buy a whole kit. You do this job every blue moon and often nothing is needed to be done, so why have a bunch of shims never to be used? You could also try to see if a shop would trade shims for a bit of money, from their shim kits.

Putting the top end back together was the hardest part for me. Seemed it took me four tries to get the cams in positioned properly, I was either a tooth or two off. Once the cams are in you should rotate just the cams by hand to pull the chain tight in the front run, all slack to the back, the cam marks should be horizontal to the head surface (unless the MCM has been done, then they should be off as noted earlier). Patience is a virtue when doing this.

Important step when you put the cam cap back on keep in mind if you break it you have to buy a whole head! So when reinstalling the cam cap be careful positioning it and push it down by hand and, if needed, some light tapping with a screwdriver handle or very small plastic mallet. The cap should fit down flush on the head - do not try to pull any gap down with the bolts, that is what breaks the casting. This is not a hard step, but very important to do it right. There are manuals available online for your bike at no cost. The engine has been pretty much the same from day one in 1994, so the torque and tightening sequence should do fine.

Put in the cam chain tensioner and look at timing marks. With a manual tensioner, verify the cold adjustment, with the OEM tensioner you need to read about the reset. It is a good time to look at the automatic tensioner, If the underside of the plunger shaft is polished shiny and there is a visible light pattern on the teeth, the tensioner is failing to hold proper adjustment and no it is not held in place by the spring, the spring just pushes forward enough to advance the plunger, the ratchet holds position and it is quite common for them to fail. Carefully turn the engine over by hand. If when the valves are opening you meet resistance stop. The cam timing is off and a valve is touching the piston. As long as you did not turn the crank while doing the valves, this should not happen, Once the timing is verified it is time to put it all back together, fire it up.

One other tip. Sometimes the cam cover gasket can shrink. What I did to avoid any problem was, while the shims were on order I lightly bolted the cam cap on (cams out) had the chain supported inside, and lightly bolted the cam cap on, It doesn't need to be tight. This is only to hold the gasket in place without risk of any shrinkage and will keep junk out of the engine.

If this sounds like a job you can do, get a manual. Otherwise call a shop and ask about the cost. Ask how much if it comes in with the tank and stuff out of the way, if they want and need to fire it up most shops have a test gas container that hangs on the handle bars. You can save a half hour to an hour if you take off all the stuff.

Hope that helps. I may not have covered every detail, but have enough for a mechanical individual to do the job.