Cycle News - Archive Issues - 1970's

ENDURO ESSENTIALS M N "> g Pari II • Setting Up to Finish • By Ron Schneiders Somebody once said that if an enduro was run only on freeways, 40% of the riders wouldn't finish 100 miles. Regretably, that is quite true. On the recen t Greenhorn enduro, a 500 mile championship event, at least two riders were pushing their bikes before we got out of Duarte where the run was started! They had failed on city streets. There are two contributing factors to this high mortality rate. One is poor machine quality and the other is poor preparation. If your machine is unequal to the task, there is nothing to be done except to get another one, but don't be too quick to decide that it's the machine. Look at the finishing list of any cross·country event and you will see machines of almost every manufacture. Most any bike, even the most miserable, can be made reliable with enough effort and cash, but most times it's not worth the effort unless you're being paid to win. Look relistically at your bike. If metal parts break often, that's the machine's fault. If parts fall off, or the engine quits or the spark or carburetion fails, that usually is your fault. If it's the bike, sell it and buy something better. If you have one of those super high performance jobs with a 17: 1 compression ratio and 11 ports that takes 40 minu tes to start on a warm sunny day, save it for drag racing and get another bike for enduros. It's just too much trouble to make it realiable and H easy to live with." There are several hundred screws, nuts and other fastenings on your motorcycle. Not more than half a dozen at most are unnecessary_ When a nut comes off, the piece that it held won't be far behind. Quite clearly, every fastening must be properly secured. Notice that I didn't say Lightened. Some things should be tight, others shouldn't; but nothing should fall off. Locktite is your best friend for this job. Every time your remove a nut, put a little drop of Locktite on the threads before you put it back. Make it automatic. But at the same time use your head. Some nuts are better safety wired, or secured with a cotter key through both the nut and the screw. Three·M's yellow weather stripping cement has been a long-time favorite for securing nuts. It will prevent them from coming completely off but not from coming loose. Locktite is better and besides, the 3-M stuff is almost impossible to remove. If your· regard your bike as a combination of systems, you will be able to prepare it much more quickly and efficiently. The first system to receive attention is the. engine/gearbox unit. This doesn't take much normally. Check that the transmission is filled and all the nuts and screws are secure. Make sure the gearshift lever is secure and not damaged. Of course you must periodically decarbonize and replace the rings. Next is the electrical system. First make sure everything is functioning properly and adjusted. Don't forget the ligh ts, if the event requires them. Set the points and replace both them and the condensor periodically. Don't wait until they fail. If you're really serious, build in a spare electrical system that you can activate with a switch. Next waterproof. I can't tell you how to do this because every bike is different. Some are almost waterproof as they are sold; others can't ever sec'm to be made really waterproof. The most vulnerable spots are the points and the sparkplug. A tigh t fitting rubber Sparkie is a must on the spark plug. Don't take any substitutes. They're cheap and they work. The points must be protected at all costs. Use Silicon-Seal bathtub caulking around the cover and screw holes and wherever else water can Ret in. When you get all fInished, see if you can drown out the electrical system with a garden hose. If you can, dry it out and start over. ext do the carburetor and air cleaner. If you ride ,vet enduros, the carburetor must be just as invulnerable as the electrical system. Foam elemen ts in air cleaners, such as FiltroD, are very effective against dust, but useless against water. They must be enclosed in some sort of box with an air intake high up under the seat or gas tank. Some sort of naughayde shield around the carburetor is a good idea, but make sure you can get into it in a reasonable length of time. Don't plug the vent holes in the carburetor unless you're sure it won't hurt anything. There's a vent on the side of the Bing carb that does let water in, but the engine won't run well if you plu,! it. The one under the intake manifold can be safely plugged. Use silicon seal, to make sure no water can enter from the top of the carburetor. The exhaust system is just as important as the intake, but is more often neglected. An exhaust pipe that fails can cause bum t valves in a four stroke engine and can make a two-stroker fail to run at all. The first step is to make sure the pipe or expansion chamber is fastened properly. If there is a flange at the head secured by studs and nuts, safety wire is a good idea. The heat makes Locktite and 3-M somewhat chancy. Be sure the expansion chamber is decarbonized or replaced once in a while. (The latter is better; Expansion chambers have a limited life expectancy anyway due to heat and vibration.) The expansion chamber is a very vulnerable item. On most bikes it is the part most likely to be qarnaged in the inevitable spill. For my money, a low pipe has no business on an enduro bike, some guys insist on running low pipes for a variety of reasons. If you must, figure out a good way to protect it. Welding a piece of angle iron to the bottom of the pipe is one solution but it reduces the ground clearance (which is probably already inadequate) even further. A skid plate that is really adequate is usually very hard to make. Nevertheless, something must be done or the first log or big rock will put you out of business. Most enduros req uire a silencer or muffler. It's best to fit one, tune your bike for it and leave it in place permanently. The,jetting on most bikes must be changed to accommodate a silencer so don't switch back and forth. If you use a silencer with some sort of glass pack, the glass must be replaced periodically, along with the mesh that holds it in place. The suspension system doesn't require much periodic maintenance but careful inspection is a must. For maintenance, make sure the oil in forks is sufficient, and the seals are in good shape. Beyond that, though, every piece of the suspension system must be examined very carefully before every run. The suspension takes a ferocious pounding, particularly in so·uthem California desert riding. Look for damaged bearings in the steering head, for bent shock absorber rods, for sacked springs, for tweaked fork tubes, or twisted swing arms and especially for hairline metal-fatigue fractures. These are not uncommong ailments; all but the tweaked swing arms and forks have occurred on my own bike which is less than one year old. When you have completed the suspension, go after the wheels and brakes. First are the bearings. If they're not the sealed type, make sure they're greased periodically, and quite often if you ride in water. Check all the spokes and wire them together so that if one breaks, it will stay in place and not damage anything else. Naturally, if there lUIS :The sound that kills the sight. .. Most Powerful .. ... .. MAleC .. COOPER MOTORS "" "" w' sell &S"~~:REO MAl CO:het8! are dings in the rims, they should be banged out. As you tighten spokes, the threaded end might protrude and damage the tube_ Check the inside of 'the rim and grind off the end of the spokes if necessary. For my money there is no substitute for rim locks. It's true, they do make it harder to change a flat, but they enable you to finish the run with a flat if the distance isn't too great, or to get into the noon check. Nothing else will allow you to ride on a flat for any distance. Period. Tires aren't that expensive; don't run them until they look like drag slicks. The less thread dtere is, the beller your chance of getting a flat. Use good quality tires and tube. Tires are an individual matter because of variations of tread design and intended use. In my experience Metzler tubes are best, followed by English Dunlops. The drive system consists of the sprockets, chain and shock absorber cushion (if any). My system of chain maintenance is to run the chain 500 miles and oil it with some kind of foamy lubricant whenever possible. At the end of 500 miles, I replace it. Occasionally I replace it more often if the enduro is really severe. (Snow, for instance, seems to annihilate chains.) At this rate it cost about $1.25 per run for chains which is really pretty cheap. Sprockets don't require much attention but the bolts holding them in place do. Use every means at your disposal to keep them from coming loose. It's a very common problem on many types of bikes. Moving upwards, to the front of the bike, check all the controls and their associated cables. Control levers should be the unbreakable alloy types and the pivot points should be protected from dirt and water by leather or naughadyde shrouds. I've found that the molybdenum disulfide lubricants work well on cables. For insurance, tape an extra cable to the one being used. Then if onc breaks, it's easy to fix in minimum time. Check the handlebars for cracks. You'd be surprised how • ~ _ntllRl'£ AMERICAN • 132. E. AllURT•• CAlI'. (lU Ill· 1117 t'D en % West of Mississippi 2: 110 E. Santa Anita Ave. Burbank, Ca. 91502 (Please tum to page 30) : Yamaha & : • • : Triumph : : of Fontana : : Sales 'a,ts Sen;ce : • Maico, DKW, CZ, Hodaka, BMW· 9008 Sierra Ave. ~~ • ~~. • Fontana, Calif. • (714) 822-2252 • • • • .****************. SEE MOTORCYCLE SPORT AND THE MEN WHO RIDE "ON ANY SUNDA Y" A Film By Bruce Brown BELL HELMETS WIN AGAIN! More professionals win with Bell Helmets than any other helmet in the world. Should you settle for less than professional head protection for your motorcycling or motorsport activities? CIQ Insist on ~ .~***************. I,chlS Sales & Service 6624 Atl..t;c,'e",C,. (213 )SBJ-3983 .... en often handlebars break. Just a few more items and you're through. The seat is one item that quite often fails with little warning because the owner forgot to check for vibration cracks on the underneath part. And it can put you out of a run. Vibration cracks are also a problem on fender and gas tank mounts. To stop a crack from proceding, drill a small hole at the head of the crack. To prevent cracks, rubber mount things that are subject to vibration. If you put rubber mud flaps on your fenders, you'll ride mud runs in a lot more comfort. Naturally, you must check your instruments, your speedometer and clock. These two items are quite often the most troublesome on the bike. They are subject to damage from both shock and vibration. The best way to mount them seems to be a metal ring with a loose network of rubber holding the speedo or clock. Speedome ter cables always break in the middle of the run in which you're doing the best you've ever done in your life. Be prepared; carry a spare inner cable. The only thing we haven't checked is the frame. It usually doesn't require any maintenance but it does require a good once over for cracks and breaks. Don't skip this one. It could be very painful if something lets go while you're making up time at 6:0 per. Husqvarna Penton 8E~ lllJ lL t~is mark on every helmet you buy :; .., ~ w Z W ..J U > U

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