So do starters. And while we can write article after article about battery charging and installation, they’re a fat lot of good when you’re standing outside work with a motorcycle that doesn’t want to, you know… do motorcycle stuff.
One of the things you can do to get a bike runnin’ is informally known as “pop-starting” the bike. It’s a way to bypass the entire starting system and instead use the bike’s drivetrain to turn the engine over fast enough to make it run. If you practice doing it before you get stranded somewhere, you’ll possess a useful skill that might allow you to save your own bacon at some point. Here’s how to do it.
Understand the limitations of the pop-start
Pop-starting a bike is not a magic bullet. It doesn’t work in all situations, nor does it fix all problems. Push-starting a motorcycle just eliminates the need to use the starting system. Be sure, then, that your battery or starter is at fault. Pop-startin’ won’t help if you have a bum clutch safety switch, no gas, or a faulty coil. Know also that older carbureted bikes with points-style ignition are usually a little more forgiving of a bad battery than something new. Modern bikes have fuel injection and electronic ignitions, both of which need electricity to function and to make the engine run. However, those modern pieces are pretty sensitive to battery voltage, so the next section may differ a little depending on what you’re riding.
Be aware that even if you do have just a bad battery, there are two types of “bad” — there’s “sort of works” and we also have “doesn’t work at all.” If you left your ignition on all night and everything’s dead as a doornail, trying to pop-start it is probably a waste of time. (That’s an example of “doesn’t work at all.”) A good “rough test” on whether or not a pop-start will work is by looking at the headlight. If the battery has enough juice to shine the headlight fairly brightly, you can probably pop-start your bike. That indicates the battery has some juice — with luck, enough to operate the fuel pump on a fuel-injected motorcycle, for example — but not enough to turn over the engine. (There’s your classic “sort of bad.”)
The other thing to absorb is that this is a way to get home. Running any bike, new or old, on a battery that may have been severely compromised places a real strain on your charging system, which is much more expensive, complex, and difficult to access than a battery. Getting home is one thing. Trying to get by for a season is another. Pop-starting is a way to avoid spending money on a tow truck, not to avoid buying a new battery.
Assuming you’re in good shape and you have a battery that’s just a little under the weather, you want to make this task as easy mechanically as possible. Having one or two friends handy is helpful, but not required. Having an incline is also helpful, but not required. I’ve pop-started small bikes by myself without a hill, but I’d say most of the time you want either help or a hill, and it's great if you have both.
Ideally, this is something you’re going to do well away from traffic. You’ll have sketchy lighting, and you’ll be riding erratically, with nincompoop friends pushing you along. Use your noodle and be safe.
Push the bike to the top of the incline. Longer is better. A really long hill can give you multiple attempts on the same trip down (but it’s also a longer walk back up.) At this point, get the bike pointed downhill, and if you have friends, tell them to get ready. Make sure your engine stop switch is in the run position and the key is on — this is mission-critical!
Select your gear
No, I am not talking about helmet and jacket. There are two schools of thought on pop-starting. Most people I know will put the bike into second gear and pull in the clutch. Second is a good choice because once the engine fires, it won’t lurch as hard as first gear. Personally, I prefer to begin my roll in neutral, because you’re not fighting the additional drag of the gearbox.
If you started in second, pull the clutch in and get the bike rolling down the incline (either by “paddling” your feet or having your pals push you.) If you started in neutral, do the same thing. I’d reckon about eight to 10 mph is about the speed to shoot for; it ain't a precise science. If you’re going down a real steep incline, you may get moving faster than that, and it’s OK. If you’re getting a push from friends, you’ll hear them huffing and puffing, and when the bike is moving as fast as they can get you, you’ll feel yourself separate from them. That's fast enough!
The moment of truth
If you started in second, dump the clutch. (Or “pop” it, hence the name of this technique.) If you started in neutral, with the clutch lever pulled in, shift into second right before you do this. Don’t “feather” or baby the clutch; then it will just act as a brake. You need to slingshot that sucker; just let it snap into place. (If you’ve ever shot a semi-automatic handgun, it’s similar to chambering a round. Just let go; don’t “ride the slide.”)
What’s going to happen
Ideally, the bike purrs to life, and you can then smoothly control speed with the accelerator. This happens most often with smaller bikes with low compression and multiple cylinders. Heavy machines with one or two big jugs or high compression might act differently. They might “chirp” the rear wheel, sliding and skidding rather than turning over. If this happens, don’t fret. Give it another shot if you’re still rolling at speed down a grade. If you’re not, have your buddies repeat the process. If it coughs and sputters, or perhaps the lights get bright for a moment, you're on the right track. If the bike is dark and silent, I wouldn't waste too many pushes.