Service
SERVICE
Paul Dean
Blubbering ’Busa
Early last spring, I took delivery of my 1999 Suzuki GSX1300R Hayabusa. By August, I had 3500 miles on the bike and started having problems with stalling, rough idling, dying at speed and coughing. My dealer told me there was some kind of recall on the bike involving fuel filters that were being deteriorated by certain gasolines. They fixed it, but three tanks of gas later, same problem. This time their explanation was that the filters are so fine that they’re filtering out the additives in the gas. They said it wasn’t covered by warranty, so the fix cost me $80, but 375 miles later, the problem occurred again. The reason that time, per the factory rep who looked at my bike in the shop, was that the filters were clogged with silt and dirt from the gas 1 was using. Another $80, and here we go again. Next time this happens, I’m changing the filters myself, and it’s not an easy job. I buy the same gas for my two dirtbikes, all my cars and my 916 Ducati and have never had any such problems with them. I also drained the tank on my Hayabusa and found no trace of any silt, dirt or water. Can you possibly help? Charles A. Goss
Newmanstown, Pennsylvania
This past September, American Suzuki issued a dealer bulletin describing a potential problem with the screens in the fuel pump and fuel petcock on earlyproduction Hayabusas. The screens were too fine to cope with the additives and contamination levels that are present in many of the gasolines sold across the country. The screens tend to clog, starving the engine for fuel and making it sputter, run poorly and stall. That bulletin also advised that Suzuki was making coarser-pitch screens available as a remedy for this problem, and that the cost of their installation in affected Hayabusas would be covered under the factory warranty.
Your letter did not specify whether your dealer was replacing the screens or simply cleaning them. If he is doing the latter, the problem is likely to continue indefinitely. But if he has replaced the screens with the upgraded units, you need to get Suzuki more involved with this problem. After all, you ’re not refining your own gasoline; you buy it at the same outlets as everyone else, and they aren ’t having these problems. You should not have to bear the expense of having the filter screens cleaned or replaced every few hundred miles.
I suggest you take the ’Busa back to your dealer and insist that he contact Suzuki ’s Service Department for further clarification and resolution of your problem. If you don’t get satisfaction, call Suzuki ’s Customer Service Department (714/996-7040) yourself and try to have the problem solved-at no cost to you—through those channels.
Just say no to cracks
I have a 1982 Honda CB750C that I purchased four years ago. It had brandnew tires at the time, but the front tire now has developed small cracks in the sidewalls, and it loses about 2 psi of air pressure per week. Although there is plenty of tread left on the tire, should I spring for a new one anyway? My mechanic said maybe yes, maybe no. I’d appreciate your opinion. I’d hate to have a blowout. Tom Gardner
Posted on America Online
Here ’s a simple rule to follow: If you have any doubts whatsoever about the integrity of a tire on your motorcycle, replace it. Immediately. It doesn 't matter how old or new the bike is, how much mileage it might have accumulated, or if you intend to ride it at a roadrace pace or at little-old-ladv speeds. The price of a new tire is insignificant in comparison to the damage, both financial and physical, that the failure of a faulty old tire can cause. When your body gets slammed into the ground at 65 mph, it won’t care whether it just got tossed off a brand-new sportbike or an 18-year-old UJM; the bones will be just as broken, the wounds just as painful, the recovery just as long.
Incidentally, the cracks in your tire ’s sidewalls and its high rate of air loss probably are unrelated. More than likely, the tire has developed a leak somewhere else, perhaps in the valve core or maybe through a small puncture in the tread. This is just one more excellent reason to replace the tire.
By the way, I suggest that the next time you ask your mechanic a critically important question, you might insist he give you a more conclusive answer than “maybe yes, maybe no,’’ a cop-out reply that is totally absent of any information whatsoever. Either that or find a new mechanic.
Big power, small leak
I have a ’97 Triumph T595 Daytona that is all stock except for a full-race exhaust system made by Westcoast Performance. The exhaust has a high, left-side exit and uses a carbon-fiber canister. I had the bike tested on a Dynojet dynamometer and it made 107.9 peak horsepower. I’ve noticed a small amount of air leaking out of the very back end of the exhaust canister where the metal meets the carbon. If you think this leak could be killing any horsepower at all, I ask your help in contacting this company because I have not been able to find their phone number or address. Scott Chase
Orlando, Florida
If the leak is as small as you make it seem, fear not; it won’t have any effect on your Triumph ’s power output. The volume of exhaust that can sneak past that joint is too small to make any difference in performance. As evidence of that fact, your Daytona ’s peak output is nearly 8 horsepower greater than that of the T595 we ran on a Dynojet dyno in 1997.
If you find the leak really bothersome, you can repair it yourself. Apparently, some of the muffler’s fiberglass packing has either shifted or gotten blown out, allowing exhaust gases to reach the joint around the end cap. If the canister is like most, you can remove the end cap by drilling out the pop rivets; then just locate some new silencing material (most bike shops sell it), repack the silencer as tightly as possible, and reinstall the end cap with new pop rivets. If you still need to contact the people at Westcoast Performance, either write them at 300 E. Coronado St., Anaheim, CA 92806, or call them at 800/222-6011.
Takin’ it to the streets
I just converted my ’99 Yamaha WR400F into a dual-sport playbike by adding a complete DOT-approved lighting kit and speedometer. After talking with a very knowledgeable and quite aggressive rider (who rides 15-20,000 miles per year both onand off-road, and owns a ZX-11, ZX9R, XR600R and two KTM 300 E/XCs), I’m worried that riding on pavement with a non-cushioned rear hub designed for a
dirtbike will quickly damage the transmission. Are my concerns warranted? Will using a synthetic oil help slow down wear and tear? Would I be wise to avoid pavement as much as possible on my dual-sport adventures? Errol Overkamp Cedar Falls, Iowa
Your concerns are justified, but that doesn’t mean you have to abandon the idea of turning your WR400F into a dual-sport bike. It simply means you need to be a bit careful when riding on pavement.
When engineers develop an off-road-only model such as the WR400, they design critical components to survive when faced with the kinds of loads and stresses the bike will encounter in its intended environment.
Anyone who uses that bike in a different environment takes the chance that some of those components could suffer premature wear or failure. In your case, the lack of any cushioning, mechanism in the WR400’s driveline, combined with the near absence of reartire slippage on paved surfaces during aggressive street riding, can stress not just the transmission, but the clutch, the primary drive and the final drive.
On the other hand, the WR ’s driveline is far from fragile. It is designed to withstand the considerable shocks delivered by normal off-road riding-jump landings with the rear wheel under power, full-throttle acceleration over whooped and choppy terrain, and so on. So, if you avoid things like power wheelies and hard upshifts on the street, your WR400 will likely survive your dual-sport adventures with no problems. And no, the use of synthetic oil will not do much to deter the kind of damage caused by shocks transmitted through the driveline.
if just keeps hangln9 on
I recently purchased a 1990 Kawasaki ZX-10 with 4000 miles on it. It runs fine except when I start the engine after the bike has been sitting for a while. When I shift into low gear for the first time, the bike will jolt forward a few inches and then stall. It will do this even if I let the engine warm up for a few minutes. It acts like I forgot to disengage the clutch before shifting into first. When I restart the engine and shift into first again, it goes into gear normally. This problem won’t occur again for the rest of the day, or even if I start it up cold the next day; it only happens after the bike sits for a few weeks. Did I purchase a bike with a major problem? CmKm71396
Posted on America Online
Your ZX-10 does have a problem, but not a major one. What you have described are the classic symptoms of sticking clutch plates, a condition that usually occurs with wet clutches (meaning that the clutch runs in oil) after the bike has been sitting unused for quite a while.
Several factors can cause this problem. If the oil is very dirty or too thick, or if it is not suitable for motorcycles that use the same oil to lubricate the engine, transmission and primary drive, it can cause the plates to cling tightly to one another even after the clutch lever is squeezed and the plates have been relieved of the force exerted by the clutch springs. What’s more, some of the highperformance clutch plates sold in the aftermarket tend to stick together more readily than stock plates.
There are two possible solutions, both relatively simple. First, try changing the oil, using only a grade recommended by Kawasaki-depending upon your climate, anything between a 10w30 and a 20w50 with an SE or SF rating. If that fails to effect a cure, replace all of the fiber clutch plates with new stock plates and the problem should disappear.
Got a mechanical or technical problem with your favorite ride? Can’t seem to find workable 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; or 3) e-mail it to CW1Dean@aol.com. Don’t write a 10-page essay, but do include enough information about the problem to permit a reasonable diagnosis. And please understand that due to the volume of inquiries we receive, we can’t guarantee a reply to every question.
