Service

SERVICE

Paul Dean

Shoulda used FedEx

I have a ’96 Suzuki Katana with about 60,000 miles on it. A few months ago, a package I was carrying came loose and got caught in the rear tire, locking up the wheel (okay, you can stop laughing now). The motor shut off instantly and the bike skidded to a stop. I was only going about 25 mph in second gear when it happened. The bike seems to run fine now and goes through the gears okay, but there’s a small oil leak coming from behind the countershaft sprocket. Is there a seal back there that might have gotten damaged, or could the force of the tire locking up have cracked something?

Edward Papendik

Mesquite, Texas

Immediately, if not sooner, either you or your mechanic needs to pull the countershaft sprocket cover and the countershaft sprocket itself off your Katana and closely inspect the engine cases around the transmission output shaft. There s a very good chance that the force of that sudden stoppage has cracked one of the cases, causing the leak you describe. If there indeed is a fracture, it could quickly and unexpectedly spread to the point where the cases break apart around the output shaft. That could not only cause the rear wheel to lock, but any oil that might be blown out of the cases could get onto the rear tire, causing a crash.

The output shaft does have a seal, as well as a bearing behind it; but with rare exception, sudden rear-wheel lockups do not hurt the oil seal unless the bearing also is badly damaged. You claim that the gearbox still functions properly, so it’s unlikely that the bearing was affected, although you would be wise to check it anyway. And don ’t delay; replacing the engine cases is an expensive proposition, but replacing the cases and repairing the damage-to both the bike and its rider-from a serious crash would be a lot more costly.

Redline? What redline?

During a recent spirited outing, I accidentally overrevved my ’92 Honda CBR600F2 while passing a car. The engine began to misfire, and when I glanced down at the tach, the needle was dropping from beyond 15,000 rpm. I completed the ride, but since that incident, the engine has had a slight miss at all rpm. What happens when an engine overrevs? Is my engine toast? Gary Baran

Scottsboro, Alabama

It's probably not toast, but it no doubt got a little scorched around the edges. To overrev your Honda s engine, you must have accidentally or prematurely downshifted. If not, there s a problem with your F2 s ignition system. The solid-state ignitions on modern motorcycles incorporate electronic rev-limiters that prevent the engine from accelerating past a predetermined safe rpm. The limiters either dramatically retard the spark or stop firing the plugs altogether, or, in the case of many fuel-injected models, cut the supply of fuel to some or all cylinders.

Rev-limiters only keep an engine from overrevving with the throttle; there is nothing to prevent it from revving too far if the rider downshifts at a speed greater than the bike could normally attain in that particular gear. If for example, you downshift from fifth to fourth at 110 mph and your bike will only accelerate to 100 mph in fourth before the rev-limiter kicks in, the engine will spin way past its maximum safe rpm, because there is nothing to stop it from doing so. Overrevving causes the valves to float, which can then allow them to hit the tops of the pistons. When that occurs, any valves that make contact with the pistons are likely to bend or break.

Evidently, that’s what happened with your F2. You claim that it only has a slight miss, so chances are good that you slightly bent just one valve. You need to perform either a cranking compression test or a leak-down test to determine which cylinders have been affected. Repairs will involve removing the cylinder head to replace any bent valves, and to inspect for possible damage to the valve seats, the cylinder head and the piston crowns. If the overrev did not occur as the result of an inadvertent downshift, you should have the ignition checked and, if necessary, replaced to prevent the problem from happening again.

Wheel weights

I’m getting ready to replace the 21-inch spoked front wheel on my Harley-Davidson Dyna Wide Glide with a chromed solid wheel. The new wheel, from ProOne, feels like it is twice as heavy as the stocker. Will this added weight cause any problems? Walter A. Sarzynski

Hanceville, Alabama

/ don’t know if it will cause “problems,” but it certainly will have noticeable effects on your Wide Glide s steering and ride quality. A wheel that’s nearly twice as heavy will practically double the unsprung weight (any part of the motorcycle not supported by the suspension s springs) at the front of the bike. So, in accordance with Newton’s Third Law of Physics-which states that for every action, there is an equal and opposite reaction-a heavier wheel being forced upward by a bump will cause a greater reaction by the rest of the motorcycle. Translation: a rougher ride.

What’s more, the heavier wheel will make the steering feel more ponderous. The greater mass of the wheel alone will add slightly to the effort required to turn the front end, and the additional gyroscopic effect created as that heavier mass spins will offer even more resistance to turning. None of this will make the bike scary or dangerous to ride, but you may be disappointed with the outcome.

Weepy Softail

I have a 1995 Harley Softail Custom that has 55,000 miles on the clock. Ever since I switched from H-D oil to Mobil l synthetic, the engine has begun to leak from the base gaskets and the pushrod covers. Have I made a mistake in switching oils? Should I just change back to the Harley oil?

Clark Ferrill Little Rock, Arkansas

There is nothing in synthetic oils that causes leaks, just as there is nothing unique about the gasket or O-ring materials used in Harley-Davidson engines that makes them vulnerable to synthetic oils. / think the problem is that your '95 Softail has 55,000 miles on it and is due for some maintenance. The cylinder-base gaskets on H-D Evo engines are prone to leakage anyway, and O-rings tend to harden and lose their sealing capacity when exposed to high temperatures for a long time-say, seven years and 55,000 miles. Besides, those repairs will need to be made in any event, because even if you were to switch back to Harley oil, the leaks wouldn’t stop on their own.

Who let the dogs out?

My 1985 Kawasaki Ninja 600R has trouble going into neutral. It makes a lot of clutch noise at idle, and I’m pretty sure the carbs need to be synchronized. I’m hoping the problem isn’t the shift forks and instead is something simple. I got the bike with 19K on the clock and have put about 4K on it since, but it has had this problem since I bought it. Your input would be much appreciated. Sb4299

Posted on www.cycleworld.com

If the gearbox otherwise shifts normally; especially between first and second, the shift forks are not the problem; and the synchronization of the carburetors has nothing to do with finding neutral. The problem is most likely with the clutch, and it may or may not be related to the noise at idle. If the clutch is not fully disengaging, finding neutral can be very difficult because the loads on the gear-engagement dogs in the transmission are not being released.

Shifting into neutral on Kawasaki streetbikes is usually a cinch because their transmissions use a clever but simple dexice called a positive neutral finder. It involves a little steel ball in each of three holes on the inner circumference of the sliding dog that engages first gear on the transmission output shaft. When the rear wheel is not moving and the gearbox is in first, that engagement dog and shaft are not spinning, which allows at least one of those balls to drop into a groove around the circum ference of the shaft. Then, when the rider lifts up on the shift lever, the engagement dog can only slide far enough to disengage first gear; the little ball stops it from moving any farther and the shift le\’er won t continue moving upward into second. So, to find neutral, all the rider has to do is bring the bike to a stop in first gear and yank upward on the shift lever; the lever will stop when the gearbox is in neutral. When the rear wheel starts moving again, the centrifugal force of the dog's rotation slings the balls up inside their respective holes so they can ’/ interfere with thefirst-to-second shift.

I've never heard of one of these devices causing problems with the selection of neutral, but I suppose it is possible. Rut before worrying about that, you need to have the clutch inspected by someone who understands its workings to determine whether or not it is fully disengaging and why it is making noise. Re prepared to replace not only the clutch plates but perhaps the outer clutch hub, as well.

If you billet, they will come

I would like to know where I can get some of that "billet" Brian Catterson and many other motorcycle journalists keep referring to. What’s wrong with calling it what it is, such as 6061-T6 or 2024-T6 or whatever the material happens to be? "Billet" just means a piece of something-or did the guy who made the top triple-tree on that R90S ("Born Again Boxer,” January, '02) find some kind of “new wood” that’s very strong? Come on, guys, not all of us are boneheads out here.

Marty McAllister

Durham, North Carolina

You are correct in pointing out that, in and of itself, the word “billet" is rather unenlightening. Rut in the motorcycle business over the past decade or so, particularly in the custom-Harley community, that one-syllable term has come to be used as short-speak to describe anything “machined from a chunk of relatively high-grade aluminum." I know, I know, we journalists are supposed to be the watchdogs of our beloved language, so we promise that in the future, we will try> to remember to specify the actual material.

White we 're on the subject of proper nomenclature, let's talk about “tripletree.” That, too, is a commonly used term, hut the component in question actually is called a “triple-clamp,” so named because it clamps the fork unit in three places: the right fork tube, the left fork tube and the steering stem. How the word “tree ” ever got in there is a mystery. Must’ve been some bonehead.

Recall Roster

NHTSA Recall NO.01V278 Harley-Davidson Motor Company Model: All Dyna Glides Year: 2001

Number Involved: 25,711 Dates of Manufacture: July ’00-July ’01 Defect: Certain motorcycles were built with a fuel hose that could come off the carburetor. Should this occur, fuel could spill, possibly resulting in a fire.

Remedy: Dealers will inspect the motorcycle to ensure that the fuel hose is correctly installed on the carburetor. If the hose is installed incorrectly, the dealer will remedy the condition. Owners who do not receive the free fix within a reasonable time should contact HarleyDavidson at 414/342-4680.

Oval is, like, so over

Could you please help me understand why Honda went to oval pistons on the NR500 and other bikes? I am considering buying a motorcycle and 1 want to get a technologically advanced machine. Do oval pistons give more horsepower per volume of displacement? Are there maintenance issues with oval pistons? Jeff Pickles

Boulder, Colorado

Interesting question, Jeff, but you 're at least a decade out of date. There hasn't been an oval-piston motorcycle built since 1992.

Honda began developing an oval-piston, four-cylinder, four-stroke Grand Prix racebike, the NR500, in 1977, and first raced it in 1979. A fter four years of embarrassing results, the NR500 was abandoned, and Honda then began development of two other oval-piston machines: a turbocharged NR250 Twin for GP use and a normally aspirated NR750 Four for endurance racing. The 250 never really got off the ground, and the 750 managed only a mediocre-at-best track record. By the mid'80s, development for racing purposes had ceased and Honda turned its attention to producing an NR750 oval-piston streetbike, which didn't materialize until 1992. Only a few hundred of these $60,000 collector’s items were ever manufactured, after which the idea was laid to rest. No other oval-piston motorcycles have been built since then.

A thorough explanation o f why Honda pursued oval-piston technology would require far more space than is available here. But the bottom line is that oval pistons were Honda’s way of circumventing an FIM rule that prevented 500cc GP race bikes from having more than four cylinders.

Ideally, Honda would have preferred to build a V-Eight four-stroke for the 500 class, but the rules prevented it. So, with the oval-piston engine, Honda essentially designed a V-Eight that connected adjacent cylinder pairs with straight-sided walls, resulting in half the number of cylinders, each with an oval shape. Each oval cylinder had eight valves, two sparkplugs and two connecting rods, just as two round cylinders would have had.

In theory, at least, an oval-piston engine should make more power per volume of displacement. And I am not aware of any unusual maintenance issues with oval pistons. It’s a moot point, though, because unless you re willing and able to find one of those rare Honda NR750s and pay its owner the ridiculous sum of money he 'll want to part with it, you can't buy an oval-piston motorcycle.

Got a mechanical or technical problem with your beloved ride? Can’t seem to find reasonable solutions in your area? Maybe we can help. If you think we can, either: 1) Mail your inquiry, along with your full name, address and phone number, to Cycle World Service, 1499 Monrovia Ave., Newport Beach, CA 92663; 2) fax it to Paul Dean at 949/631-0651; 3) e-mail it to CW1Dean@aol.com: or 4) log onto www.cycleworld.com and click on the Feedback button. Please, always include your name, city and state of residence. Don’t write a 10page essay, but do include enough information about the problem to permit a rational diagnosis. And please understand that due to the enormous volume of inquiries we receive, we can't guarantee a reply to every question.