how to know when you need a valve adjustment
 

How do I know when I need a valve adjustment, when my F4i has about 22k miles on it.

The manual recommends checking them at 16,000 mile intervals. No way to know except to dig in and check them with a feeler gauge or have a mechanic do it. I've heard some say, "they're OK if they're not rattling", but if they're rattling, adjustment is long overdue. They can be out of adjustment and not be noisy enough to catch your attention, but will still affect the bikes performance. The more loose the valve clearances are, the less lift you're getting from the camshaft. Not to mention accelerated wear on the parts from the excessive clearance beating things to death.

Good question. I just had mine checked and found 6 were tight, and 2 were almost past the recommended distance. How does the "rattling" sound? Because the cam chain rattles too.

that's a good one, in fact i dont know either if my bike need valve adjustment, she has 37000 km and i think it never has been adjusted BUT she runs fine to me.

right after you check valve clearances!!!

You can look at the valve cover to get a feel if it has been checked before. Excessive or messy gasket sealer between the head, gasket and cover point to it being removed for atleast a clearance check. I adjusted mine somewhere around 36k. They had been adjusted before. If you do it properly you will feel a noticable change in the engine. By properly I mean measure clearances, adjust clearances, re assemble and SYNC the throttle bodies. Without the sync the engine will not perform as efficenty. If the valves have different clearances that means that air/ fuel intake and exhaust are not the same for each cylinder. By not synching the TB's the intake mixes are not the same, meaning each cylinder performs differently. A properly adjusted and synced engine will idle smoother and have a lower idle.

Feeler guages, Gasket sealer, and a synch device are necessary to do the adjust. You should also have a torque wrench and basic math skills. You can go to a dealer with your valve shims and most will swap your old ones out for what you need to bring them back into spec. If they won't swap them out go somewhere else. I bought a valve shim kit and diddnt even use it. The shims in the hotcam kit are in larger increments than what I needed to make my clearances right.

You can buy what you need to do the maintence for less than a shop charges. Mae sure you have a shop manual, and atleast 3 days to do the service in a well lit clean workarea. If you've never adjusted valves shim under bucket it is a bit intimidating at first. This is not something to rush through (is any maintence?). Take your time, do it right. You'll save money and have better understanding of your machine and greatly improve your mechanical abilities.

^ no joke about syncing...I checked my valves over winter break and didn't sync. My timing belt skipped a few teeth. Bike wouldn't start because there was no compression and I cried myself to sleep for a few days.