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Archive for November, 2009
Today we conclude our week-long look at snowmobiles. It all began Monday with an exploration of a typical sled’s drive system. From there, we compared and contrasted snowmobile tracks with those of a tank. Yesterday we posted some brief thoughts on the environmental impact of snowmobiling and the importance of replenishing two cycle oil. Now let’s head even further down the trail to discuss safety tips.
As is the case with any vehicle, you must familiarize yourself with the terrain before deciding to see how fast you can go. You wouldn’t drive 55 mph in a car down a narrow residential street for obvious reasons. Even if you’re riding a snowmobile in a secluded spot, the quality and condition of the snow will make a huge difference. Snowmobiles are set lower to the ground than motorcycles, which might lead you to believe that there’s less risk of injury. Bear in mind, however, that the open sled design creates a very real possibility of falling off.
The most critical pieces of safety equipment for a snowmobiler are the helmet, gloves and boots. Gloves and boots help keep the extremities safe from frostbite, which can nip away at fingers and toes to make precision steering a difficult task. When sledding in a populated area, snowmobilers must be familiar with conventional hand signals – they’re very similar to the ones used by bicyclists. For example, a right turn is signaled by sticking the left arm straight out to the left. A right turn is signaled by pointing a bent left arm upward.
In the past few days our discussion of snowmobiles has run the gamut from power systems to track mechanics and steering. Today, it’s time to take a step back from the nuts and bolts to see the forest for the trees. Just what are the environmental implications of recreational sleds, and what plans are in the works to increase engine efficiency? Unlike the environmental effects of automobiles and boats, those of snowmobiles remain understudied and to some extent uncertain.
The history of snowmobile engines reflects that of outboard motors in one key way. As recently as a few decades ago, both were being manufactured with little regard for their environmental impact. The amount and content of exhaust emitted by the engines was eventually deemed unacceptable, and the rise of four-stroke engines challenged two-stroke manufacturers like Yamaha to step up their game.
Today’s snowmobiles feature reduced emissions and increased engine efficiency. Where once speed and maneuverability were a sled’s main selling points, eco-friendliness has now joined the list. Modern-day snowmobiles run best on specially formulated 2 stroke oil. Snowmobile manufacturers continue to struggle with noise pollution concerns, however. Many sled makers have taken concerted steps to reduce noise levels.
In yesterday’s installment, we took a look at the four main components of a snowmobile’s drive system: the engine, clutch, track and skis. We’ll shift gears slightly today to focus on the track in particular and the steering system in general. The track is designed to maximize traction as the sled moves along the snow. It could be likened to that of a tank, with one major difference: tank tracks are stiff and durable above all other considerations because of the role they play in warfare. Snowmobile tracks, on the other hand, are meant for optimal swiftness and maneuverability.
It goes without saying that snowmobile tracks are more effective on snow than wheels would be, but why is this so? The answer comes down to a question of physics. By spreading out the point of contact with the snow to a larger surface area, tracks create plenty of traction. The treads on the track are rough enough to create friction and grab onto the snow at regular intervals.
Snowmobiles steer in much the same way as other vehicles with handlebars. However, the steering system brings up another major difference between tank tracks and sled tracks. Tanks are often given outfitted with double tracks, which are charged with steering. Snowmobiles come equipped with twin skis at the front of the sled. The width and spacing of the skis make a significant difference when steering. Narrow skis allow a snowmobile to take sharp turns. Tomorrow we’ll take a look at the improvements that have been made to 2 cycle oil formulations.
Last week we presented a four-part series on seasonal snowmobile maintenance – the kind of repair work that should be done even before the best powder begins to fall. This week, we’ll take it back to basics, explaining the ins and outs of the snowmobile from its drive system to its steering system, from environmental impact to safety tips. For those of you who already go snowmobiling on a regular basis in winter, this should prove a valuable refresher. For beginners, it aims to serve as a good informational starting point.
The sled’s drive system can be broken down into four essential parts: engine, clutch, track and skis. While some four-stroke engines are available in professional snowmobiles, lightweight models feature a powerful two-stroke. The engine links to the internal track drive, which in turn causes the tracks to rotate. In a way, snowmobile tracks are like those of a Sherman tank – except scaled down considerably, of course. Snowmobiles always benefit from a fresh supply of Yamalube oil.
The clutches are really a glorified pulley system that connects to the track drive and tightens the belt around the track. Most snowmobiles have a primary and secondary clutch. The secondary clutch comes into play once the sled has accelerated; it “shifts into another gear” once the wheels begin to turn and less effort is required on behalf of the motor. The skis are fastened at the front of the sled to provide stability. We’ll talk more about them in the entry on steering.
Over the last few days, we’ve discussed the ins and outs of a seasonal snowmobile tune-up – from salvaging the upholstery to checking for exterior scratches and ensuring proper fluid levels. In today’s final installment, we’ll shift over to one of the most common causes of engine failure: the filthy carburetor. It doesn’t take much more than regular hand tools, a can of carb cleaner, some ingenuity and a willingness to get your hands dirty.
For those who don’t already know, the carburetor is the device charged with mixing air and fuel in an internal combustion engine. Commence the cleaning process by crimping fuel lines to prevent any leakage while you work. Remove any throttle cables that might get in your way, as well as the fuel lines. Loosen and remove the carburetor, then inspect it for residue.
If residue is found to be blocking the two main jets in the main carb body, place the carburetor in a bath of car cleaner. It should then be blown dry and inspected once more. Reverse the procedure to reinstall the carburetor. That’s it! Before hitting the trail, it’s never a bad idea to top off your snowmobile with Yamalube 2s oil. Happy sledding, and remember to drive safe.
We continue today with part three in an ongoing series dealing with snowmobile maintenance. With winter temperatures already established across many areas of the country, those powdery drifts of snow likely aren’t far behind. In order to keep your sled running with reliability and efficiency all season long, it’s best to perform a scrupulous preseason tune-up. Let’s go under the hood to check the integral inner workings of the sled.
By now you might have noticed a pattern inherent to these visual inspections, and the process of checking the drive belt is no exception: looks for cracks and other blatant signs of wear and tear. A belt is just one of several spare parts that an avid snowmobiler should keep on hand at all times. Next, find your throttle and oil cables, checking to see if they’ve been damaged in the offseason or have become frayed with use.
Perhaps most importantly, make sure that all fluid levels are correct, including coolant, brake fluid, chaincase oil and 2-cycle Yamaha oil. Checking chaincase oil can be rather tricky depending on the make and model of your sled, so be sure to consult the owner’s manual first. Don’t just take it for granted that your fluid levels are low and simply need to be topped off. In many cases, there’s a reason for dramatically reduced fuel levels – and it might be a costly, mechanical one.
For as long as I can remember my parents have been avid boaters. Whether it is waterskiing, fishing or just taking a cruise around the lake, they can’t get enough of the water. In recent years they have both been bogged down with work, so our Bayliner has been neglected in a storage shed.
This summer we all finally had some free time and were able to take the boat out on one of the local lakes. Usually my dad is religious with the upkeep of Shirley-as he calls his boat-but after not being taken out for years, we had to do some quick maintenance before launching. My dad and I had to completely flush the engine, replace some rusted bolts, and fill it up with Evinrude XD50 oil.
Today we pick up right where we left off in our preseason snowmobile maintenance process: the visual inspection. Having checked for cracks in the hood, we now turn our attention to the upholstery. Seat covers may become nicked and scratched with use, and in some cases they might slip right off the mounting. These details might seem trivial or superficial, and it’s true that your snow machine can operate no matter the state of the seating. Now is a good time to shore up any aesthetic flaws, however. Try gluing a similar fabric underneath hole in the leather or synthetic seating.
Now it’s time to get a look at the underbody of your snowmobile – specifically, the track and the rear suspension. Check for bent or broken suspension parts and ensure that the sliders haven’t deteriorated. When inspecting the track, think about it the same way you would the tires on a car. The slightest sign of wear is more than enough evidence in favor of replacement. Driving with a worn track is basically tempting fate; you could end up walking several miles back to civilization through deep snow.
Tip the sled onto its side to get a glance at the skis and runners. Again, you simply have to check these parts for serious signs of wear. Steel skis should last you many years provided they aren’t bent or allowed to corrode. Plastic skis could be cut or otherwise impacted rather easily, so check them with added prejudice. If you haven’t already done so, top off the engine with Yamalube 2s oil. Tomorrow we’ll go under the hood!
Now that November’s icy chill has replaced any thoughts of summertime fun, many outdoors enthusiasts are putting their boats away for winter. We’ve discussed proper winterization techniques in the past, but now it’s time to focus on an equally invigorating recreational pastime: snowmobiling. No matter your preferred outdoor pursuit, it’s important to conduct a preseason checkup.
By ensuring that your sled is ready and equipped for snowmobile season, you can save yourself constant trips to the repair shop. Over the next few days, we’ll investigate the most common problems that afflict snowmobiles in the offseason and attempt to diagnose a solution. The first step might seem brutally obvious – your snow machine has probably been lurking in a far corner of the garage, so you’ll have to remove the sizable layer of dust that’s settled on top of it.
Either take your snowmobile to a local carwash or do the work yourself with a garden hose, a sponge and a bucket of sudsy water. Once it’s clean, you’re ready to begin inspecting the outer areas of the sled, beginning with the hood. Be on the lookout for any signs of serious wear or neglect – cracks in the outer body, deteriorating hood latches, decals peeling off, etc. In tomorrow’s update, we’ll continue with the visual inspection and eventually go under the hood to replenish the old supply of Yamaha 2s oil.