Service

SERVICE

Paul Dean

The charger from hell

I just purchased a new battery, a Yuasa YB18L-A, for my ’86 Kawasaki Concours. This is the bike’s fourth battery, including the original. According to everything I have read, a new battery should be slow-charged at 1/10 of its rated capacity for 10 to 18 hours before use. But before installing this battery, the dealer fast-charged it for less than 30 minutes.

This worries me. The second battery, which lasted only nine months, also was fast-charged. The original lasted five years and the third almost four, and both were slow-charged. I got all four batteries from different dealers, but both of the shops that did the fast charges told me that the battery manufacturer would not honor the warranty unless the battery was fast-charged. One of them even claims he bought a special charging machine from Yuasa, and another says he paid over $600 for his special fast charger.

Is this fast-charging business legitimate? Also, should I trickle-charge the battery with a 0.5-amp charger for 30 minutes daily when my bike is not in active use or should 1 charge it only when it is dead? Scott Stiles Victoria, Texas

Your “fast-charge ” dealers are positively dead-wrong. Their claims about charging rates and Yuasa warranty policies are complete hogwash. Under no circumstances should any battery ever be charged at a rate that exceeds 25 percent of its ampere rating. Yuasa, in fact, strongly recommends that the charging rate never exceed 10 percent of the ampere rating, whether the battery is new or used. Ideally, the charging rate should be 1 amp or less; and if the battery is completely dead or heavily discharged, it will need to be charged at least 18 hours, probably longer. The length of the charge will depend upon the battery's condition at the time the charging is begun. The only accurate way to know when a battery is fully charged is to cheek the electrolyte with a hydrometer.

When your bike is in storage, it s a good idea to trickle-charge the battery at one ampere or less on a regular basis; do not wait until it is dead. Batteries tend to lose their charge at the rate of about one-percent per day, so your suggested charge rate seems appropriate. Better yet is to use the Battery Tender, made by Deliran (801 U.S. Hwy. 92 East, De Land, EL 32774; 904/736-7900), which is a charger specifically designed to keep batteries properly charged while in storage. You connect the Battery Tender to the battery and leave it there throughout the storage period; it charges at a 1.25amp rate until it senses that the battery is fully charged, then it automatically switches to a minuscule, 10-milliamp rate. Any time the battery's voltage drops below 13.2, the Battery Tender automatically reverts back to the 1.25amp rate until a full charge is attained.

The dogs of wear

I have a 1991 Honda ST 1 100 that currently is showing 4200 miles, and it doesn’t shift very precisely in first through third gears. When 1 engage these gears, the transmission seems to place the gears near each other, but they don’t engage with a “click"; they seem to ride over each other with a fair degree of rattling for a second or so, then engage. No other noises or problems are evident. 1 recently test rode a 1994 ST1 100 and it did not make this noise; the shifts were silent and precise. Is this something 1 should be concerned about if I plan to keep the bike for between 50,000 and 100,000 miles?

Jeff Rabenda East Windsor, New Jersey

There are two likely causes of this problem: one mechanical, one involving technique. First, the clutch on your ST might not be disengaging fully, even when the lever is pulled all the way to the handlebar. This would cause the dutch to drag slightly not enough to prompt any of the more obvious symptoms of incomplete disengagement (difficulty in finding neutral at a stop, or the bike 's tendency to creep forward when idling in gear with the clutch disengaged), but enough to prevent quiet, smooth gearchanges.

This problem is evident only in the lower gears because the ratio differences between first and second, and between second and third, are quite large, while differences between the third and fourth ratios, and especially fourth and fifth, are comparatively small. As a result, the differences in the speeds of the two engaging gears is much greater when you shift from first to second and from second to third than they are during the two other shifts. And if the clutch has just a bit of drag, the engagement process can be noisy in the lower ratios as the two mating gears try to equalize their significantly different speeds.

Then there's the possible technique problem. People who treasure their motorcycles often "baby" them in an attempt to keep everything in like-new condition, so they sometimes have a tendency to shift gears too gently. But motorcycle gearboxes are designed to be shifted rapidly and with a brisk, deliberate movement of the lever. This allows the gear dogs (the engagement devices on the sides of the gears) to mesh almost instantaneously upon initial contact. If the shift is made slowly and gingerly, the gear dogs will bang off of one another—particularly if a dragging clutch impedes the quick equalization of gear speeds-until the dogs can engage. This is the rattling noise you describe.

So, your mission is twofold. First, make all of your gearchanges quick and positive, not slow and tentative. And second, either you or a reputable shop needs to determine if your ST’s clutch is releasing completely. Check the fluid level in the clutch master cylinder, and bleed the system to ensure that it contains no air bubbles. If you are using any engine oil or additives that do not comply with factory recommendations, stop doing so immediately. If none of these actions cures the problem, you 'll have to disassemble the clutch assembly and check for warped plates or a badly notched clutch basket.

Ride ’em, Kawboy

1 ride a 1993 Kawasaki ZX-11 and am having problems with suspension setup. I'm 6-foot-4 and weigh 225 pounds. I get to the backroads as much as possible and ride fairly hard, so 1 prefer a setup for more sport-oriented riding. After some experimentation, 1 have adjusted the front-fork spring preload at two clicks from the stiffest setting, and the fork rebound damping at the fourth (the stiffest) of its settings. The rear-shock damping is also at the stiffest of four settings.

At speed, I have a hard time determining what should be done to correct certain flaws in the handling. In fast corners, I get a wallow or sway from the rear and a pogo feeling up front. On straight roads with a lot of pavement imperfections, I feel like I’m getting beat up. Sometimes, on parts of the expressway that are like mini speed-bumps, the rear end completely leaves the ground, almost throwing me from the bike unless I’m standing, dirtbike-style. Can you tell me what would be the best setup for my height and weight and a sport-riding style?

We tackled this same dilemma two years ago with a ZX-11 project bike (“ZX-11 For The Long Haul,” August, 1993 issue). The problem with the big ZX is that it has excessive compression damping at both ends and toosoft springing up front. Only the rebound damping is adjustable, so there’s little that can be done without internal suspension modification.

To that end, we sent the suspension to Jim Lindemann at Lindemann Engineering (520 McGlincey Lane, Unit 3, Campbell, CA 95008; 408/3716151), who, for $280, modified the fork damper rods, shortened the fork springs and revolved the rear shock. When we got it back, we set the fork damping at the second of four positions and the preload on the sixth of eight settings, and used a 1 Omm-higher (150mm) level of 10-weight fork oil. At the rear, we set the rebound to the second of four positions and adjusted the preload to give 1.5 inches of rear-end sack with the rider aboard.

With these modifications, our ZX11 was significantly more compliant than stock on rough pavement while also maintaining a lot more composure and stability in fast corners. S3

Christopher Corbett Farmington Hills, Michigan