Why things are the way they are: Dirt bikes and electric starters

Jun 15, 2017

E·lec·tric foot /ih-lek-trik foo t/ noun 1. Slang for a motorcycle fitted with a push-button starter

I like ancient bikes and dirt bikes, so my boots spend lots of time stompin' on kick starters. But it's starting to look like the kicker's days may be numbered. Kawasaki introduced its 2018 off-road model lineup a few days ago, as did Yamaha. Team Green still relies on boot power to get its big MX bike running, but Yamaha now uses electric starter on the YZ450F to wake it from slumber. Why the difference? Perhaps a little history on motorcycle starting is in order. 

When it comes to motorcycles, there’s two main ways to start ‘em up: electrical starters or foot-powered kickers. On the street, kickers pretty much saw their last usage in the 1980s, with the occasional curious exception, like Urals and the Yamaha SR400. However, in the off-road world, the kicker has endured a bit longer for a few reasons. 

Blue bike
Yamaha has just joined the ever-growing list of OEMs who no longer require foot power to get their bikes rolling. Yamaha photo.

The first off-road machines were all kick-only, simply because that was the most reliable way to get a bike to start. As starters became smaller and more efficient, though, it made sense to include them on some off-road bikes, as well. Starters and the requisite batteries and wiring did impose a weight penalty, but it was sometimes worth it. Motocross racers didn’t necessarily want the extra lard, but for a woods rider, electric start could be nice. Starting a bike mid-hill after a stall with just a push of a button had some appeal, as did not having to kick a bike after laying it down several times in a short period when attacking challenging sections of trails.

In some cases, electric start supplanted kickers, rather than joining them. Some manufacturers offer both options, which can be helpful for those who are far out on a trail and may have suffered a bum battery. (KTM is notably including both kick and e-start on many of its woods bikes.)

Orange bike
Ryan Dungey doesn't have a kicker on his bike. Should you? KTM photo.

The switch to four-stroke engines also increased the desirability of an electric starter. Four-strokes are considerably harder to kick, due to greater compression. Kicking a two-stroke in most cases is not too objectionable for most riders, but a four-stroke generally requires more effort — not a good thing when you’re pooped on the side of the trail. Yes, it was possible to fit a decompression release (and the manufacturers did!), but that added cost and weight. Often, the dirt crowd of yesteryear prized simplicity and low cost. The decomps weren't a magic bullet, either. They just made things a bit easier.

Dual-sports, being street legal, need to have a battery-operated lighting system. (Most jurisdictions want the lights to be operable if the bike is not running, for breakdowns and such.) Trail bikes also had lighting systems, but theirs could generally be operated without a battery.

And this was the way the world worked until recently. Big trail bikes slowly moved from being kick-only, to either electric and kick, or even electric only. Motocross bikes, being race machines, still included kickers to keep weight down. Once the bikes are started, they usually run until the race is over, and any extra weight is dead weight. (Ever notice there’s no sidestand on a motocross bike?)

Now, we're starting to see electric start on some motocross bikes. Why the change? There are a few reasons.

Having a battery onboard can provide a few advantages beyond starting. A battery serves to help “smooth” electrical pulses; motocross bikes are becoming more complex electrically. Modern MX bikes have fuel injection and light off their mixture using electronic ignition for ease of maintenance and accuracy in timing. Fuel pumps and CDI boxes are exceptionally sensitive to voltage changes — a battery can make them more effective and longer-lived. Increasingly, electronic rider aids are showing up on these machines, as well, which makes a battery pretty appealing from an electrical standpoint. If a battery must be present, why not trade the kicker cover, gears, and lever for an electric starter, eh? Similar weight, less work for the rider. The weight penalty is less than in the old days. A quick case in point: A 2006 KTM 450 SX-F, a kick-only bike, weighed 231 pounds. A 2017 model, fitted with electric starting and no kicker, weighs in at 221. 

Then there's another reason. Race bikes are all about performance and winning. Let’s rewind to the Las Vegas Supercross of last year. Ryan Dungey, aboard a KTM, was involved in a crash with Ken Roczen, atop a Suzuki. Watch the crash and the resultant restart times.

If you advance frame-by-frame (use the period and comma buttons while the video is paused), you'll see that both riders get their bikes upright at about the same time. Note that Dungey, who actually went down after Roczen, is up and running in about one second. Keep watching, and you’ll see about seven seconds elapse before Roczen’s bike moves under its own power. The difference? Ken was kicking. Ryan hit the “magic button” and started putting miles under his wheels. Seven seconds in a race can be a long, long lead. Dungey went on to win. Perhaps Honda's move this year to make 2017's optional electric starter standard on the 2018 450 MX models was inspired in part by Roczen's performance on that Suzuki, eh?

Anyone who’s ever attempted a hot start on a pissed-off, freshly righted 450 can tell you it can be a bit of a chore, both physically and mentally. (Did I flip the hot start lever?!) Racing is very much about having the correct equipment, and in that race, a starter appeared to be the right piece of kit.

Another reason riders are demanding e-start is likely to be one of cost/benefit ratio. In real dollars, dirt bikes are a bit more expensive nowadays than they once were. Many top-line dirt bikes are regularly selling for five figures. I think that there are some riders who simply expect a few more amenities at a given price point — after all, isn’t that what R&D is for?

Green bike
Is Kawi a stubborn dinosaur holdout, or is there more to the equation? Is the simplicity of a kicker now outmoded with current starter technology? Kawasaki photo.

Starter efficacy plays a part, too. Some of us are old enough to remember when electric starters on motorcycles were a curse; a novelty to be used on the odd days the system deigned to function as the optimistic engineers had hoped it might. Nowadays, though, starter and battery technology have improved (starters much more so than batteries) and electrical engineering has improved by leaps and bounds. Simply put, as Ryan Dungey demonstrated for us, ‘lecky starters work, and they work well.

This leaves me with a few questions. Will there be kick-only holdouts? Is Kawi catering to a specific market? The Kawi is not lacking in technology; they were one of the first to bring out launch control. So why no electric start? I think they may simply have invested money in the last redesign, and now they're being "leapfrogged" this year by Yamaha.

Perhaps most importantly, what do you prefer to see on your off-road bike? Do you think there's going to be a rash of "old guard" riders scrambling to buy what may be some of the last kicker MX bikes on the market? Does Suzuki have something up their sleeve for 2018?