Engine, Transmission, Chain

What’s the best way to break-in an engine?

Run it hard! And read the rest of this explanation.

How often do I need to change the oil?

There are several schools of thought on this. Some say you should change your oil every 3000 miles; others say every 6000 miles is fine. In any case, you should change it every 3 months.
Paradise Garage has interesting formulas.

Should I use petroleum-based oil or synthetic oil?

Yes. BMW doesn’t recommend synthetic oil until the engine is broken-in.

I notice that many bikes seem to require 10w-40 oil. Most manufacturers, of course, recommend their own specific name brand. What difference really is there from motorcycle-specific oil and auto oil?

American Iron and Motorcycle Consumer News have done tests on oils and found that the difference between motorcycle-specific and auto oil is nil. The old yarn about SJ oil being deadly for motorcycles is false, as oil with viscosity 10w30 isn’t bound by the government’s low-phosphorus, low-zinc requirements. This is the crux of the car-oil myths.

How often do I need to lubricate the chain? What with?

Every 600 miles or 1000 km, either spray wax chain lubricant or pour some gear oil on it.

How often do I need to check the chain’s tension? How?

Every 600 miles or 1000 km. Your motorcycle’s Owner’s Manual will have directions.
With most motorcycles, you check the tension with the bike on its side stand. I found that with my Honda CB-1 up on a shop stand, I could get the tension right. The key is to have the suspension at the correct sag.
You need to check the tension at several points along the chain’s travel around the engine and wheel sprockets. The tension should be set so that the loosest spot and the tightest spot are still within the slack tolerance specified in the owner’s manual. If the tightest spot is at the tightest allowed and the loosest is beyond the tolerance, then it’s time to get a new chain and sprocket set.

Do I have to replace the sprockets at the same time I replace the chain?

Yes. It’s likely that the sprockets are worn. Putting a new chain non a worn pair of sprockets will make the chain wear out faster—and replacing the sprockets without replacing the chain will sear out the sprockets. Do them as a set.

Fuel System, Exhaust

What grade (octane rating) of fuel should I use and why?

Use the minimum octane that does not cause your engine to knock. Anything more is wasted money.
High Octane Gasoline Facts.

Do I need to turn the fuel valve off to park the bike overnight or longer? Does it do any harm to leave it on?

If the float valve is in good shape and everything else is OK, no, you don’t have to turn off the fuel petcock. However, if anything isn’t perfect you’ll have, at best, gas all over the bike and the floor. At worst, you’ll fill one cylinder with gas and the other cylinder will fire when you try to start it and you’ll go into hydro lock and bend a connecting rod. Do you feel lucky?

What’s the best money I can spend on making my motorcycle go faster?

A couple hundred bucks on a track school.

What does it mean to “re-jet” the carburetors?

Carburetors supply a mixture of gasoline and air to the engine. The gas comes out of little things called “jets” (usually a pilot jet, needle jet and main jet). If you modify your airbox or exhaust to flow more freely, you get more air going through your system. This often means that there is not enough gasoline, so the engine runs badly. “Rejetting” means replacing or modifying some of these jets so as to supply gasoline differently than stock, usually more gasoline than stock. If done correctly, this allows your engine to generate more power, run a little cooler, start and run smoother and get worse mileage.

Tires, Suspension, Steering

I want to put bigger tires on my motorcycle. How can I tell what will fit?

No, you probably don’t want to put bigger tires on your motorcycle. They will probably make it handle worse, not better. To some people, bigger tires may look better, but to those in the know, they make the bike look like the owner doesn’t know anything about motorcycle suspension and steering.
Do you think you know more about suspension and steering than the engineers who designed your motorcycle?

How do I break-in my tires?

If you take aggressive turns on new tires, you may dump your bike. New tires may have sticky or slimy goo on them, either mold-release compound from the manufacturer to make sure the tire comes out of the mold, or lubricant to let the tire slip more easily onto the rim. (Tire manufacturers and installers deny that such materials exist.) In any case, new tires are smooth and have limited traction. Take turns gently, slowly increasing your angle of lean. Slowly is the key: You always want enough of the contact patch to be on the broken-in section that you don’t lose it. Eventually your chicken-strips will disappear.

What are chicken strips?

As you lean more on your tires, you wear-in more and more of the tire, and the road surface loses its fresh-from-the-mold sheen. Chicken strips are what’s left on either side. When I got new tires, I photographed them after the first 50 miles. The picture of the front tire shows the chicken strips.

What’s the difference between radial tires and bias-ply tires?

The main difference between radials and bias-ply tires lies in their construction. Tires aren’t just toroidal balloons, they are reinforced with cords of steel or synthetic materials such as nylon or Aramid. In bias-ply tires, the fibers are wrapped in an X pattern between the beads; in radial tires, the fibers are wrapped perpendicular to the tread. Radial tires have more flexible sidewalls than bias-ply tires, and thus absorb road irregularities better and have a comparatively larger contact patch when leaned over. Because of the flexible nature of a radial, these offer higher mileage compared with a comparable bias-ply for a given rubber compound. Since they absorb small road irregularities better, they ride more comfortably and are less likely to be upset by groovy pavement.
While radial tires perform better than bias tires, some older motorcycles can’t be fitted with radial tires because of differences in rim profiles. You probably won’t notice much of a difference anyway, so stick with boas tires if that’s what the motorcycle was designed for.

Why can’t I mix radials and bias tires?

The different ways in which radial and bias tires react to sideways loads can lead to unpredictable behavior while cornering. It’s bad enough to do this on a four-wheeler, but it can be even worse on a motorcycle. If you need to replace one tire and the same type is not available, then go ahead and replace both tires with the same type.

What do “Cartridge Emulators” do?

Old style forks used damper rods to control oil flow, and thus damping. The damper rods are simply calibrated holes through which the fork oil is forced during suspension travel. Cartridge emulators replace the damping rods with cartridge valves. It’s generally not as good as a true cartridge fork, but they’re much better than damping rods. More information can be found in “Cartridge Forks” by Paul Thede.

What do “Steering dampers” do?

A steering damper is a miniature shock absorber for your steering. They look a lot like precision built versions of a screen door closing rod. It will attach on one end to the frame, and the other to some point which is steered, usually one of the triple clamps. (I’ve seen them attached to the fork tube below the upper triple clamp as well.)
They will slow down steering input, and their primary benefit is found on bikes which get their front wheels light or off the ground altogether under acceleration. They’ll help prevent you from turning the wheel while it’s light/off and thus produce a wiggle, wobble, or tank-slapper when the wheel is loaded up again.
When there is a large differential between the width of the front and rear tires, there is an increasing chance of a “tank-slapper” when you hit a bump in a corner. Now, to be fair, many times this is more a result of incorrect suspension settings or wrong tire air pressures. But having a great disparity between tire widths enhances the chances. Now, you don’t want a huge wide front, or your steering will feel like that of an old worm-and-roller work truck. You don’t want too narrow of a rear because then you would not have the traction to lay down the power in some of the more brutal sport bike motors. And lastly, having a large disparity in tire width makes a bike more responsive in steering turn-in. So a compromise is struck, basically. Sometimes, people (or manufacturers) push things too far in one direction for ultimate stability, and that’s where a steering damper becomes useful in preventing tank-slappers from growing out of control

What will cartridge emulators and steering dampers do for me?

Let you ride faster and still be within the performance envelope of your bike.
Give you bragging rights about how technically advanced your motorcyle is.

What’s the difference between handlebars and clip-ons?

Clip-ons are individual bar-lets which usually attach to the upper fork tubes, one on each side. Some sport/touring bikes have risers attached to the “clip-ons” which raise them well above the top triple clamp. Regular bars are cheaper, usually heavier, and easier to customize. Race-grade clip-ons usually have easily and cheaply replaceable tube sections, providing you haven’t damaged the actual clamp section, but not a whole lot of street bikes with “clip-ons” stock have cheap replacement tubes. Generally, you will find clip-ons on more sporty bikes with more aggressive riding positions.

Inverted fork: useful design or drunken engineers?

Less unsprung weight. Stiffer front end, more resistant to deflection. Increased cost, in many cases. Most people don’t have any use for the “improvement” on a street bike, but if the bike you’re looking at has them, and the bike is not crazy expensive, they’re nice to have.

Electrical System

I want to add auxiliary lights. Does my alternator have enough extra capacity to do this?

Maybe. The new BMW oilheads defnitely do, but sportbikes tend to have alternators big enough just to run the existing electrical devices and charge the battery.

Can I use mineral water to put in the battery?

No! Those minerals will break the battery. It has to be distilled water.

How do I take care of my motorcycle's battery?

See the Car Battery FAQ.

Other

How do I get the bike up on the center stand?

1. Start with the bike on its side stand;
2. Grip left handlebar with left hand;
3. Grip frame member with right hand;
4. Place foot on center stand lever;
5. Pushing down on center stand, tilt bike till both legs of center stand touch ground;
6. Push down hard with foot and lift/pull on frame member.

Where can I find a web site about my motorcycle?

Google is your friend.

How do I secure my motorcycle?

Lock the steering to one side with the ignition lock. Use a disk lock. Use a large lock with a chain around something solid. If you use a disk lock, also get a bright ribbon that says something clever like “Remove Before Takeoff” so you don’t forget to remove the lock before you break your brake disk. Keep the motorcycle out of sight … or in a brightly-lit area. Keep it under a cover, with a better lock than the other motorcycles nearby. Get a bike that is less popular with thieves. Despite all this advice and all your best efforts, your bike might still get stolen.

How do I prepare my motorcycle for the winter?

In California, stick a rain jacket in the saddlebags. If you have to store your bike, Winter Storage for Motorcycles.

Should I sell my bike?

Remember: “Bikes get you through times of no money better than money gets you
through times of no bikes.” —Phineas