When Science Fails—by Allan Girdler

When Science Fails

Go ahead, look at the picture first. My bet is, you won’t be able to guess what it is, or why it’s shown here, until you read the blog, a clear case of 1000 words giving value to one photo.

How so?

Constant surfers will recall that not long ago, I bought a Kawasaki Ninja 250R, an ’05 with barely 1000 miles on the clock, perfectly shiny as new, at a fair price even when I had to ante up the fees to re-register the bike after two years in storage.

I hauled it home, did the insurance and registration, checked the oil and coolant and tires, set choke and hit the button, and it fired right up. After a proper warm-up, I rode down to the county road, pleased with the lightness and precision of steering and brakes.

Three miles later, the engine staggered and surged, feeling as if it was out of gas, although I knew it wasn’t. Revving and using the choke, I stumbled up to my stepson’s ranch, where the engine died dead as Marley.

Home in my truck, feeling as puzzled as angry, as in the seller gave me his card and asked for an invite to our gearhead lunch, meaning he hadn’t tricked or cheated me.

In the shop, there was gas in the tank, the petcock flowed freely, the spark was strong and hot…but the engine would run only on 5/6th choke, at 4000 rpm, and would not pull.

There’s a Ninja 250 website, the technical section of which has a collection of accounts of troubles just like mine, with a bike taken out of storage and refusing to run.

Every one of these reports said the same thing: stale gas or contaminated gas, as in ethanol and varnish, with the smaller jets fouled or plugged.

I spoke with Bill Werner, head of Kawasaki’s dirt-track team; Randy Davis, retired Kawasaki technician; and our own Paul Dean, head of our Service department and a man of vast experience.

They agree: What we had there was a carburetion problem.

In matters like this, I am a vintage guy. If it’s a round-slide Mikuni or even dual Webers, or a single-fire magneto, I’m yer maun.

But a check with the Ninja shop manual showed me I’d have trouble removing even the air filter, so I called in Bill Formby, a retired racer who is Mr. Fixit in my neck of the woods.

Oh, dear. The Ninja’s two carbs were checked out. At this point, science and careful analysis and logic indicated that was the problem, but it didn’t seem that way, nor did the performance improve after all the passages and orifices had been cleaned and inspected.

Paul had recommended a jetting kit, as he’d ridden Ninjas so treated and found them improved, so I got a kit from Dynojet.

Short pause here. At this point, all the sources had used careful review, step-by-step scientific inquiry. All clues pointed to a problem…that wasn’t there.

So, with the carbs back on the bench, with the body panels off the frame, Bill began looking elsewhere.

My Ninja is, of course, a California model. The 49-state Ninjas feed air to the fuel tank through a vented cap. The California version, fearful lest fumes foul the atmosphere, have a sealed cap with a labyrinthine network of purge hoses, drain hoses, vacuum hoses, pulse hoses, feed hoses and canisters.

Yes. The mystery photo is of a section of the hose that feeds—or is supposed to feed—air to the fuel tank. If air can’t get in, fuel can’t get out.

Somehow, sometime, some way, some one put that hose next to an exhaust pipe. It was nowhere near where it should have been. The heat softened the hose, which sagged flat and shut off the air.

The jets weren’t fouled, the carbs weren’t out of whack and ethanol, for once, wasn’t the guilty party.

How this happened, I can’t fathom. My vintage Triumph was disabled at least in part through neglect and abuse—as in a dry fork, drenched brake, botched wiring.

The Kawasaki hadn’t been ridden, much less abused. I bet it has just had its first oil change. The two previous owners hadn’t tampered or even touched anything I can find. A mistake done during assembly? Not the sort of thing Kawasakis are famous for.

Not that any of the above means much. What matters here is, to rework philosopher Eric Hoffer a bit, is that we see what we look for, so sometimes if we aren’t looking for it, we don’t see it.

And the bottom lines are: Problem solved, lesson learned.

When Science Fails

  • Don Lee

    Alan I could tell at least two stories very similar to yours. Oftentimes it is the little things that give us the most problems and bring our ride to a stop. Thanks for sharing and I will be nice and not share my tells of woe. Who said a picture is worth a thousand words?

  • Steve Palley

    I knew someone a few years back who supplemented his income by working on Chinese-made scooters, which were well-machined but were failing due to flimsy hoses and their placement. Because of this, I suspected right off what the photo showed, and the first words confirmed where it was gonna go.  We learn….

  • Steve Brown

    Interesting mystery story with a happy ending. Elementry. Thanks for sharing.