Clearing the way: Troubleshooting a snow blower

After writing about buying and mounting winter tires and wheels, I’m going to tackle the other thing you need to get out of your driveway in the winter—the snow blower.

For nearly 10 years, I’ve cleared snow with my little Honda HS520. It’s a diminutive thing, looking sort of like a lawnmower with indigestion wearing a snorkel. It’s a single-stage snow blower, which means it’s not self-propelled. Well, it’s sort of self-propelled—it drags itself forward on the pavement using the same rubber paddles employed to throw the snow. Its small size and relative light weight allow me to move it around easily, even loading it into the back of the wagon or the Suburban (when I still had one) if I needed to do my mother’s driveway. It works acceptably well in less than six inches of dry, powdery snow, but as the snow gets heavy and deep, it bogs down.

Honda, of course, is known for its high-quality products, and their snow blowers have a one-pull reputation for starting, but there are limits, and I routinely exceed them. Garage space is precious to me, and, I’m sorry, but the snow blower doesn’t push out the vintage BMWs or the Lotus, so it sits outside under the back deck. It was already a used machine when I bought it, and the last 10 years have taken their toll. I’ve replaced the rubber paddles, the belt, the plug, and the ignition coil, but even with powdery snow, its performance seems to be degrading over time—and in wet snow, it’s nearly useless.

For the past four years, I’ve vowed that this would be the HS520’s last winter. This summer, I intended to be proactive and scout out a bigger, better used Honda, maybe one of those medium-sized machines on tracks that folks seem to rave about. I planned to check Craigslist and yard sales, be a shark, and see if I could pounce on a good deal from someone who’d had enough of winter and was moving to Florida. But I never got around to it.

As it happened, about two days after I bought the winter wheels and tires and got them on the BMW X5, the first snowstorm of the season was to move into New England. I half-heartedly looked online at used snow blowers, but the problem with wanting something bigger than the little Honda is that it will be difficult to simply show up, buy something, and throw into the back of the X5 without both partial disassembly and two young, strong assistants (which I do not have), and if you’re looking for something used where the seller is willing to deliver, it dramatically cuts down on the selection. So, as they say in the military, I prepared to go to war with the army I had.

But then, like an idiot, I left myself zero time for the “prepared” part. The afternoon the snow was forecast to hit, I dragged the Honda out from under the back porch, filled it with fresh gas, opened the fuel petcock, and was about to try to start it when I noticed fuel streaming out from under it. I pulled the cover off and got ready to do battle. There was about an hour of daylight left, and the very first spits of snow were beginning to fall. I’ll use that pastoral (though slightly stressed-out) backdrop to have a poignant, almost cinematic flashback into my automotive history.

The snowblower, un-covered.
The snowblower, un-covered. Rob Siegel

People come to car craziness and automotive repair via a variety of vectors. A common one is small gas engine maintenance and repair, with lawnmowers, chainsaws, and snow blowers being the gateway drugs to go-carts, minibikes, and motorcycles. I, however, did not take that route. I probably would have, but I was diverted. When I was in junior high school, I actually tried to take a small gas engines shop class, but in Amherst, Massachusetts in the 1970s, there was a social divide between the “greasers,” who were generally children of the farmers, and kids like me, who had a college-employed parent (never mind the fact that I was a middle-class kid whose single-parent mother was not a professor but worked in administration). When I walked into that small gas engines class, I saw that it was populated with the kids who bullied me in school. The vibe that I didn’t belong was palpable. So I left.

I came to automotive repair, oddly, through bicycles. I built and rebuilt bikes, salvaging them from the garbage, stripping them down, and combining components. It was from there that I learned the general ins and outs of mechanical systems. I later applied that to fixing cars. When I was 18, bought a Triumph GT6+ and it overheated, I saw coolant streaming out from the front of the engine and deduced that the thing with the belt and the pulley was some sort of water pump, saw the bolts holding it on, borrowed some tools to remove it, hitchhiked into town to buy a replacement, and installed it. Everything that followed flowed from that path.

Now, those of us who came of age in the analog carburetor-and-points world developed an appreciation for the three things an engine needs to start and run—gas, spark, and air. Yes, there are caveats (you need compression too, and the spark has to be correctly timed), but it remains a bedrock diagnostic. Fuel delivery is often due to a bad fuel pump. Ignition issues usually trace back to the points or the condenser. “Gas, spark, and air” is certainly true of modern cars as well, but from a laying-on-of-hand standpoint, it doesn’t apply as directly. With the coil-on-plug ignition most cars have had since the 1990s, there are no spark plug wires, and with the plugs buried under false engine covers, there’s not a direct way to check for spark. With high-pressure fuel pumps controlled by the engine’s ECU in response to the input from a variety of sensors, and fuel lines routed deep within the engine compartment and attached with fittings more complex than simply a hose clamp, it’s challenging to verify the presence of fuel and determine what is at fault if it is not present. In contrast, on a vintage car with a distributor and exposed plug wires, and carburetor or vintage injection system, it is a simple matter to verify the presence of spark and fuel.

But even a vintage car is a level of complexity above a small gas utility engine. Fuel pump? We don’t need no stinking fuel pump; the carb is gravity fed. Distributor? One cylinder. Fixed advance. Nothing to distribute. Electrical system? None. The ignition is magneto-fired.

The funny thing is that I‘ve only learned this recently. Due to the shop class incident in junior high school, I had a big hole in my knowledge. So, yes, although small gas engines are even simpler than vintage cars and therefore should be even easier to diagnose and repair, I do sometimes need to backfill some of these holes.

Fast-forward back to the foolishness of “preparing” the snow blower with maybe an hour to go before the weather moved in, and finding it leaking when I filled it with fresh gas. I assumed that the fuel line from the tank had split, but when I looked, I saw that the fuel wasn’t coming from the feed from the tank, and instead it oddly was coming from a rubber tube hanging down from the top of the carburetor. I figured that what was probably happening was that either the float or the needle valve—or both—were stuck, that that was causing the gravity-fed fuel to overfill the float bowl, and that the rubber tube was connected to some sort of overflow port so, if this happened, gas wouldn’t flood into the engine.

The simple little carb on the Honda snow blower. The overflow tube is the black one with the red stripe center-right
The simple little carb on the Honda snow blower. The overflow tube is the black one with the red stripe center-right. Rob Siegel

Fortunately, the float bowl on this carb is similar to the ones on the Strombergs on my Lotus Europa in that it can be dropped down from the bottom of the carb. In fact, it’s held on by a single 10mm bolt. So, 28 degrees out and with the snow blower on the sidewalk, I undid the bolt, dropped the bowl, reached up and under, and felt the float and needle valve mechanism. They did feel stuck. By gently working the mechanism up and down, I appeared to free it up and restore a range of movement to it. I reattached the float bowl, rotated the petcock, and smiled at the fact that fuel was no longer streaming out the overflow tube.

The float, as seen from the underside of the carburetor. The jet can be seen in the round hole in the center. At the top of the picture, you can see the baffle plate over the intake.
The float, as seen from the underside of the carburetor. The jet can be seen in the round hole in the center. At the top of the picture, you can see the baffle plate over the intake. Rob Siegel

I flipped the ignition on, gave the rope a pull, and waited for my Honda moment.

It didn’t come. Not after one pull, not after 10. So while the snow blower was no longer leaking, it was in fact quite dead.

Ok. Fuel, spark, and air. I recalled that, years ago, the Honda died while blowing heavy snow and would not restart, and it turned out the problem had been that there’s a metal baffle plate that covers the intake throat of the carb, snow had gotten past this baffle plate, and had packed the carburetor throat, preventing air from getting in. Maybe a mouse had crawled in there and died. But from underneath I could see no visible blockage.

As far as fuel, clearly the thing had more fuel than it knew what to do with. So, the problem must be spark, right? The way you check for this in a vintage car is get a helper to turn the key, or connect a remote start switch and press it, while holding a plug wire a quarter inch from a good ground and verifying that there’s a visible spark. Unfortunately, it’s kind of hard to do this by yourself on a gas engine with a pull start.

So instead I opted for checking for spark via the indirect route—starting fluid. I use this all the time in diagnosing no-start problems in cars as either due to ignition or fuel. If you give a good blast of starting fluid into the intake and crank the engine, and it starts and runs for a second or two and dies, then clearly it has spark and what you have is a fuel delivery problem, but if it doesn’t start, there’s no spark (or the ignition is so badly timed that it won’t fire). Using one of those thin red spray tubes that WD40 comes with, I was able to get the starting fluid past the baffle plate. The snow blower started immediately, then it died. Clearly it had spark.

Now, back to gas. There’s a little screw you can use to drain the gas out of the float bowl. I turned it, and gas flooded out. So clearly it had gas. So why wouldn’t it run? It was as if the gas wasn’t getting from the float bowl into the engine.

I looked at the little peach-sized carburetor and thought, gee, there really can’t be much more in there than a float, a needle valve, a throttle plate, and a jet. Maybe the jet was clogged.

I pulled the float bowl back off and turned the snow blower over. Looking at the underside, I could see what looked like a jet, but the visibility wasn’t good enough for me to pull it out. With the afternoon light rapidly failing, the temperature dropping, and the spitting snow turning into actual flakes, I undid the metal baffle plate which allowed me to access the two studs securing the carburetor. Holding the carb in my hand, I could see that the jet was all gummed up. I unscrewed it, used a pin to clean it out, blew everything out with starting fluid, and put it all back together.

One pull. Vrroom. This time, it stayed running.

Now, alert readers will ask: “Isn’t it true, Mr. Siegel, that both the stuck float and the gummed-up jet were likely caused by the fact that you didn’t drain the gas at the end of last season?” Um, yes.

And, going full Perry Mason on my butt, “Isn’t it also true that you don’t routinely use fuel stabilizer of any kind?” Um… maybe.

Yeah. Well. Okay. Shut up. Sometimes we have to do things—or not do things—in order to learn our lesson.

But that’s not the funny part. Wanna know the funny part?

After getting the thing running, I waited until morning to use it. By that time, the snow had turned to rain and soaked the six inches of snow on the ground, and the little Honda was absolutely useless, with the chute getting clogged every few feet.

Two days later, I went out and bought a proper snow blower. It’s a 35-year-old vintage 5hp 24-inch Snowflite, bought from a 70-year-old guy who refurbishes and sells vintage American-made snow blowers. I probably overpaid for it, but his love for this kind of machinery was contagious. I went to his house, and his entire backyard was full of snow blowers and small yard tractors.

Had I stayed in that shop class, that guy might have been me. I’m still trying to decide whether I missed an opportunity or dodged a bullet.


Rob Siegel has been writing the column The Hack Mechanic™ for BMW CCA Roundel magazine for 33 years and is the author of five automotive books. His new book, Resurrecting Bertha: Buying back our wedding car after 26 years in storage, is available on Amazon, as are his other books, like Ran When Parked. You can order personally inscribed copies here.

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