6) Round things: Skinner Pm'd an excellent suggestion, check spoke tension. Do this by 'dinging' a screwdriver or wrench off every spoke in the wheel, and tightening those that 'thud' instead of 'ding' after you've made a trip around the wheel and taped the spokes that are loose (to look for a pattern, if they all relate somehow there may be a bigger issue at play). Even pitch everywhere is the key, small adjustments are the key. Often you'll find a spoke or two that the nipple has somehow lost like 10 turns, just tightening it back up will make your wheel much stronger.
Now is also a good time to install new tires, if you've been putting it off. I know those knobs have 1/8" of hardened, rounded old rubber left, but believe me, it'll work a lot better with the full 3/8" and sharp edges to boot. KLR guys, you listening?
7) Remove the tank and seat and as much plastic as is easy. Clean aggressively, a pressure washer can help if used with care, as can a bunch of WD-40 sprayed on everything and then blown off with air and wiped with shop rags.
Look for cracks (in anything, frame, tubing, etc), chafing of wires, misrouted or kinked cables, worn radiators or radiator hoses, airbox boot cracks, loose fasteners or hoseclamps, in general, just take your time and inspect everything while you've got it apart and are cleaning. Dielectric grease on all connections. My general rule is that if I see shiny spots, I try to understand what's happening there. If I see non-dirt-grit, I try to figure out where it's coming from. If I see dirt collecting on something, I figure out what the leak is. Your choices are to do it now, or when it strands you.
8) Engine: an engine oil and filter change goes without saying, as does a check of valve clearance. New coolant is a good idea too, and if your motor has any weak points you haven't addressed (KLR Doohickey, whatever) you may as well do it now, before you're riding the thing all the time.
This is also a good time to inspect the plug, plug wiring and so on. Obviously, look at the carb and check for vent lines that are hardened or kinked, any leakage issues, and if the engine runs rough, you may want to disassemble and clean the carb and all associated jets and passages, as well as throwing a new spark plug at it. If you've had your tank on and off a bunch, replace the fuel line, all those times being pulled and pried and grabbed aren't doing it any good.
In general, people pay the most attention to their engine so I won't belabor the point.
9) Swingarm pivot and linkage (if equipped). I know you've been putting this off, so have I.
Worn or sticky bearings will do more damage to your suspension action than any amount of suspension tuning can fix. If things are gritty or rusty, get out that hammer and drift and start replacing. As usual, Creeper's been here and done a great job for the LC4, his guide
is relevant to anything.
10) Drive: Inspect sprockets for any hooking or wear, and the chain for stretch by pulling back on the rear side of the sprocket. If it comes up off the sprocket more than a tiny bit, break out the Visa and get new stuff coming. Again, getting the last 1000 miles out of these components comes at the risk of being stranded or holing your cases or etc, and that's not ultimately cheaper. Replace as a set, and there's very little reason to run aluminum in the rear, steel is cheap and lasts a lot longer.
11) Clean or replace the air filter. I'm a big fan of the No toil line of products for foam elements, also sold as Pro Honda and Kawasaki. Use really hot water if you are using these products for the best results.
While you're at it, clean your airbox top to bottom, inside and out, for a few reasons. First, it will help you identify if there's a leak anywhere. Second, it will minimize the chance of dropping sand into the intake tract when you're doing that hurried pre-ride filter change later in the season. Third, the rest of the bike is now clean, and you're going to leave that oily mess?
12) Shock: If you haven't had the oil replaced in a while, it really does have a life expectancy of less than the rest of the bike, and you really would be well advised to do it. Call around for a local suspension guy, almost every town has one, who can throw fresh oil and nitrogen in there, and may cut you a good deal on some revalving while he's at it. You will never be sorry for money spent on suspension.
After reassembly, check your sag. Millimeters count, so it's worth paying attention to with some frequency as you change the load on your bike, you've been working out all winter and lost 20 lbs, etc.
13) Before you put the seat back on, evaluate your toolkit. Refresh the supply of zip ties and duct tape, patches and CO2 canisters, and look at some of the great tips in this thread
. Inspect your spare tube for chafed holes (or throwing the bad one under there and forgetting, DAMHIK).
14) Replace any worn fasteners as you reassemble. Worn bolt heads, stripped allen and phillips head screws, cheesy OEM hardware in whatever location- these are the stuff of nightmares when you have a small issue just before darkness falls on the trail. $5 spent at the hardware store will do wonders for ease of working on the bike.
Remember, as you work on this bike, it's going to take you places you can only dream of, and potentially, also only dream of hiking out of. Either it goes back together capital R Right, or it's wrong and you should redo it. Shortcuts in wrenching rarely lead to somewhere pretty, unlike on the road.
I urge replacing things because it's cheap relative to the alternative. A bunch of fasteners, a fuel line, chain and sprockets, a throttle cable and a few other odds and ends add up to less than the cost of a weekend of riding, and so many people are frustrated when they finally get the time to go and the bike lets them down. New bikes are no exception, I go through everything with anti-seize, loctite, and grease before I even ride it.
Reassemble, and then sit back with a beer where you can see the bike in your garage. I'm serious about this. Does everything look right? I've found lots of things I forgot in the heat of the moment by just letting my attention rest on the bike in general rather than any one part in particular.
OK, what did I miss!