After a lot of questions about how to get your CatEyes up and going, here's a list of tune-ups that helped get my beast moving! I did them in the beginning to my CatEye and have been happy with it's performance since.
They are just simple remedies to solve a few of the things that plague the bike when it comes new, in a box on your doorstep. These are not meant to teach you everything you need to know about tuning your bike, but just enough to get you started.
VERY FIRST THING... Read the Users Manual! Specs and other info for your specific bike are available there.
You'll need to take the covers off the bike. Unplug (and cut zip ties) for the taillight to take off the top cover. Take the whole headlight assembly out of the front (4 screws) OR just take the bulbs out. Either are easier than unplugging the wires and removing them from the wiring clump zip-tied to the frame. Take off the side covers (AKA farings) and the front. Now your bike is naked (except for fenders).
A bike stand will make the tuning process a LOT easier and more efficient (less tuning, riding, tuning, riding... and more tuning straight through). I made one from wood, either way you'll have to find a way to prop up the rear, then front of the bike to tune the brakes.
You will also want to use a fresh batch of precisely mixed gas and 2 stroke mix. If you try to tune your carburetor while burning old gas or wrong mixed ratios, it's not going to be setup right and your wasting your time.
So here we go...
Tighten EVERYTHING; From the front wheel's valve stem to rear wheel's, and everything in between! Anything bolted on (excluding the engine/parts) you can, add a drop of LocTite (Tite'N, ThreadLok, whatever; temp hold, NOT PERMANENT HOLD) on it and torque down. You can use it on the exhaust pipe, which should be checked often. Also, use care not strip stuff trying to bolt it down tight. Get it tight enough, and leave it! Then check all the major component every time you ride.
Adjust carburetor (idle and air/fuel mix); Learning to do this will GREATLY improve your bikes performance. A lot of the "upgraded" bikes would have been better off stock, with just a good carb tune up!
Idle: Adjust this first since it will be a lot easier to tune the air/fuel mix if your bike is idling! On the left side if the carb (left if your sitting in the bike), there are 2 screws. The bigger one on the bottom (flat tip with spring behind it) is your air/fuel mixture screw (we'll get to that one later). There is a smaller one towards the top, that just threads through a little black plastic brace and keeps the throttle arm (on top of the carb) from returning back to far, and allowing the engine to die (thats the idle screw). Here's another way to find it, looking at the top of the carb, twist the throttle and let go (remember looking at the carb, not the throttle). See the arm that moved back and forth and compressed the spring? Now the small gold screw facing you that stops that arm from spinning to far toward you... Thats the one!
Start up the bike, and if it idles to slow and wants to die, keep giving it a little throttle and turn the screw IN (clockwise). If it is revving to high, turn it OUT (counterclockwise) slowly in 1/4 turn increments until it's idling lower but steady.
Air/Fuel Mixture; This is a little trickier... You may need to adjust this to get it close, and then ride it and check it again to achieve peak performance. Start with a clean spark plug so you can gauge the settings after their made. Also, make sure the plug is gapped .024-.027 (per the Mfg recommendation).
Screw the mixture screw in all the way. Now back it out about 4 complete turns.
Fire the bike up and hit the throttle. With the bike at HIGH RPMs it will be running rough, turn the mix screw IN (clockwise) until you hear the engine starting to smooth out and pick up a little. If you go to far, you'll hear the RPMs start bogging back down (I'm at sea level and mine's about 2 turns out, but it's different for every bike/setup). You are in the right ballpark now... Ride it and see how it does, and adjust it from there.
Adjust and fix front/rear brakes; When mine came both rotors were loose, and bent! Since you already tightened them down (as per the first suggestion), now you can move on to adjustments and straightening.
First thing, check the brake cable to make sure its routed in the best possible way. Mine had a big loop of extra cable rolled up inside my farings. Things like that put extra friction on the cable, and make your levers feel sticky or sloppy.
Adjust the levers to the desired amount of play. The brakes will probably be rubbing real good about now, but we'll fix that. Start here, and you won't have to adjust the calipers again when you do the levers later.
You adjust the levers by shortening or lengthening the amount of cable that passes through the caliper (part mounted to fork and swingarm to grab the brake discs on the wheels), like adjusting brakes on a bicycle. A good trick is unscrewing the adjustment barrel (on the lever) out about half way. That way if something happens while your riding it, you can adjust the cable in or out on the fly with that (and not need tools).
Next loosen the 10mm nut on the caliper that holds the cable.
If you need to tighten the brakes and reduce the amount of lever play (and you probably will), pull MORE brake cable through the cable holder, and clamp the nut down further up on the cable. If you need to loosen the cable and add more play to the lever, slide the brake cable OUT of the caliper and clamp it closer to the end of the cable. Make sure 10mm clamp nut is tight, if it isn't and it slips when you try the lever, you get to start over!
Now roll the wheel and look at the brake caliper (part that clamps onto the rotor (AKA disc). Rotor rubbing real good? It look a little wavy, maybe rubbing on both brake pads? That's where I started.
I sized a crescent wrench to just a hair wider than the disc's width. Then spin the wheel and see which way the disc is bent. Then mark (or hold) the middle of each bend and roll it back to where you can clamp the wrench on to the center (of the bend). Use the wrench's leverage to CAREFULLY bend the disc back out in the opposite direction. Roll the wrench outward bending the rotor in the cutout area below the braking surface, and not all the way down at the hub.
THIS IS A DELICATE PROCESS!!! If not done right, you will be damaging the rotor worse than it is now... Be careful, bend a little and roll test it again. Not enough, do it some more. But don't get crazy!
Once the rotor is as straight as you can get it, adjust the barrel knob on the caliper. It's the only knob on the caliper that has lines cut around the head, so you can turn it with your fingers (and not a wrench or driver). This knob changes the angle of the caliper, to best accommodate the angle of the disc and allow it to roll freely.
The knob doesn't spin around that far, so just adjust it back and forth while rolling the wheel until you find the setting that allows the wheel to roll the best. In the end, you may need to loosen the cable a little, if you cant straighten them enough. Just try not to have the cable so loose you squeeze the levers and they touch the grips...
Mine aren't perfect and still rub a little, but I can give my (elevated) wheel a spin, and it will make 2 full revolutions. When I got it, it wouldn't make a 1/2 a rev. after I let go of it.
Adjust Chain; An over-tightened chain can put more drag on the wheel than the rubbing brakes! But a lot easier to fix... Simply loosen the axle nuts, adjust the tensioners (nuts on back of axle that push or pull the axle). If the chain is too tight, loosen the tensioners, and tighten if the chains to loose. Tighten the axle nuts back down. And if you want to add a little chain lube (any chain specific lube) now's a good time!.
Check Tire Pressure; The easiest way to make an improvement performance/gas mileage (a little improvement...). While low tire pressure increases your cornering traction, the extra drag robs your engine of power. For general use, I inflate my tires to the max allowable PSI (20 PSI).
Additionally, you can check for gas leaks, all your electrical plugs (securely joined), that the air filter/choke are operating properly (oil the filter if you do that, I don't) and any other details that will be easier to address with the covers off.
I also aligned my body panels and bent the welded on mounts into place. First I aligned the gas tank to be centered in the frame. Then fit the top cover to sit flat both in the seat area and in the front of the "tank" portion. Then I adjusted the sides to have an even space between them and the top cover. Helps for a nicer finished look when it's all buttoned up. A rubber mallet, and a big pair of vice grips worked the braces into place nicely!
If your just starting out with your bike, BREAK IT IN! Start out with a lower gas to oil ratio, (20:1 or 25:1) and don't run it real hard for the first couple/few tanks of gas. Give everything a chance to mesh together and seat properly in your engine, and it will have better compression and be a lot healthier for you in the long run!
