Service
SERVICE
Paul Dean
The Kat that roared
My 1991 Suzuki Katana 1100 has a serious problem, I think. During a trip to Mexico a few months ago, a bearing in the transmission came apart and caused a bunch of teeth to break off some of the gears. I had the bike fixed in Mexico City, and now it shifts all right except that it has this really annoying noise in third gear. It's fine in all the other gears, but makes a loud howling sound in third. The bike now has over 19,000 miles on it, 3000 of them since the repair, and the noise hasn't gotten any better or worse. Obviously, I can't take it back to the place that repaired it. Got any ideas? Darryl Dill Wichita, Kansas
Although you haven 't provided much diagnostic information to work with, it sounds (if you `ii pardon the pun) like both of the two mating gears that produce the third-gear ratio needed replacing, but that the mechanic only replaced one of them. If all of the teeth on the other gear were intact and the mechanic didn `t inspect them closely, he might have thought the gear was okay and simply rein stalled it. But the teeth could have
been damaged when the transmission failed, or it even could have devel oped uneven wear patterns as a result of normal use. Either way, mating damaged or badly worn gear teeth with those of a brand-new gear could cause the teeth to mesh improperly and noisily. It wouldn `t take much of a mismatch between the gear teeth to create the noise you describe. It impossible to say whether or not the gearbox will eventually fail again or just keep making noise indefinitely. The only way to be sure is to disas semble it and replace both of the gears that make up third gear. Do not try to save either gear, including the one you had replaced in Mexico, be cause it will have developed irregular wear patterns as a result of it meshing with a defective gear for more than 3000 miles.
In cold blood
I have a 1978 Kawasaki KZ650 that has what seems to be a simple prob lem. When the engine is hot, the bike is fast, smooth and dependable. But when it's cold, it doesn't want to ac cept any throttle. All it will do when cold is idle, and only if the choke (okay, the "fuel enrichment device") is on at least halfway. But if you wait five minutes, the thing flies, no matter how far the throttle is turned. Even in the hot summer months, warm-up still takes at least three minutes. I've checked the compression, set the float level, checked for vacuum leaks, and adjusted the carbs with vacuum gauges. None of that had any effect. I'm a British-bike enthusiast and usually don't own Japanese bikes, but I like this Kawasaki-when it's warm. Even my old Triumph doesn't act like this. I just give it two kicks with no choke, and 30 seconds later, I'm gone. Please help. Mike Kupchik Beach Park, Illinois
There `s an excellent chance that ab solutely nothing is wrong with your Ka wasaki. The motorcycle industry was just figuring out how to comply with exhaust-emissions standards back in the midto late-Seventies, so many bikes of that era were extremely cold-blooded, the KZ650 among them. Certain Suzuki models, in fact, were so cold-natured that they would refuse to carburate acceptably until ridden at least 20 or 25 miles. And some other bikes had annoying hesi tations and throttle-response glitches that would never go away, regardless of how long the bike was ridden or how hot its engine became. Your Tri umph starts with just two kicks and can be ridden almost immediately because it has carburetion much too rich to meet any emissions requirements, even the comparatively lenient standards of 15 years ago.
It also helps if you understand that chokes and cold-start enricheners accomplish the same thing in decidedly different ways. Chokes make the mixture richer by partially blocking the carb s ait-intake opening/ enricheners do it via a separate circuit that feeds large amounts of fuel into the intake stream when the “choke ” is activated. On a carb with a true choke, opening the throttle past a certain point causes the mixture to become progessively richer, since the choke valve restricts the amount of air that can pass. With an enrichener, however, opening the throttle past a cei tain point causes the mixture to become leaner, because the suction required to draw fuel up through the open enriching circuit is greatly reduced. Your KZ650 uses enricheners, so it s not unusual that the engine refuses to run at large throttle openings or higher rpm when first started.
About all you can do is give your engine a thorough tune-up, including the removal and cleaning of the carbs and all of their jets. But don t expect any significant improvement in its behavior when cold.
Intercepting trouble
I have a 1983 Honda V45 Interceptor that I greatly enjoy. It has been a reliable bike over the years and now has 16,500 miles on its odometer. But I recently read a book that claims the 83 Vf 750 has a disastrously unreliable engine. Is this true? If so, what are the faults and what can I do to correct them? Tom Lange
Euclid, Ohio
Those first Interceptors had a few mechanical gremlins, the most worrisome of which was a tendency for the camshafts bearings (which are not tollers or bushings but instead merely the plain aluminum of the cylinder head) to score and gall, thus ruining the cams and the heads. But most of those failures occurred on engines that were either raced in competition or run extremely hard on the street, or that hadn t had their oil changed at the prescribed intervals. Keep the oil clean and topped off and avoid extended runs at full throttle, and your VF750 should live for a long time. □
