Service
SERVICE
Meeces pieces
Paul Dean
For three years, I have owned a 2000 Honda VFR750F that now has 15,830 miles on the odometer. I live on the Natchez Trace Parkway (I’m a patrol Ranger there) and the bike is kept in a carport surrounded by a hardwood forest. It sometimes has to sit for extended periods, and during a recent hibernation, the air filter got infested by mice and was covered with hickory nuts, hickory nut dust, mouse feces and urine. I replaced the air filter, and my local dealer installed new plugs, even though he said the old ones didn’t look that bad for the bike’s mileage, but the engine feels like it’s running on three cylinders. The oil also got contaminated with fuel, so it was changed, along with the filter. The dealer said it had good spark and they could detect no problems with the electrical system. When I rode the bike home from the dealership, it ran better than when I took it there, but still not as well as it should. The dealer said he would do a leakdown test to check the compression on all cylinders, but the shop is
about 200 miles away and I have not yet made it there. Any ideas? Terry J. Kelly Hohenwald, Tennessee
I have no experience whatsoever with hickory-nut dust and mouse excrement in motorcycle engines, so from here on out, I’ll just be making half-educated guesses. But I have to think that at least one of the fuel-injection system ’s injector nozzles is clogged. The orifices in the VFR ’s nozzles are exceptionally tiny, and if the bike sat long enough for mice to homestead in the air filter and fuel to seep down into the crankcase, it s probable that any residual gasoline in the nozzles evaporated and left behind the same kind of varnish that clogs jets (with much larger holes) in carburetors. So if you and your dealer have indeed cleaned up all of the mouse debris, check the injector nozzles. If you find a clogged one, I suggest you replace it rather than trying to clean it; the orifices are so small that it s hard to ensure that they have been completely cleared of any blockage. The spray pattern produced by injector nozzles is a very important factor in determining combustion efficiency; an
obstruction too small to see with the naked eye could impair the pattern enough to have a negative effect on that particular cylinder ’s performance.
If the injector nozzles prove not to be the problem, a systematic troubleshooting procedure, including the aforementioned leak-down test, should be the next step. I get the sense that this would have to be carried out by your dealer, so I hope he runs a fair, competent service department. Problems like this can be difficult to track down and require a logical, step-by-step process of elimination to diagnose.
I know very little about the location where you store the VFR or what other options you have, but you should consider taking steps to prevent rodents and other wildlife from getting into the important parts ofthe bike. If you can’t park it in a more secure, closed environment, plugging the air intake might be a reasonable preventive measure, as would capping off the end of the muffler. That wouldn ’t put a stop to all possible damage inflicted by pests but would preclude most of it.
Ergo-tuning
I’ve installed handlebar risers on my 2004 Kawasaki ZRX1200R in an attempt to take some weight off of my wrists and hands, and I changed the grips to the softer foam type, but to no avail; my hands still go to sleep after 25 minutes of riding. I’m sure it’s an ulnar nerve issue. I am considering replacing the handlebar with one that has more rise and pullback. I realize this will probably require replacing the cables and brake lines and lengthening the wires, but will it also negatively change the front/rear weight distribution? I like my bike but it is extremely exasperating that I’m only able to ride for such short periods before having to stop. Larry Ribble
Redmond, Washington
Yes, installing a higher, more swept-back handlebar will change the front-to-rear weight distribution of the overall bike/rider package, but not enough to have meaningful effects on the ZRX’s handling or stability. If you were a competitive roadracer, the shift in weight bias may have a negative impact on handling, and the moreupright riding position would dirty up the aerodynamics enough to reduce the Kawi ’s high-speed acceleration and absolute top speed. But for general street riding, even at a fast cornering pace on twisty roads, you should notice no ill effects. In fact, you may even find that you ride the bike more smoothly and capably in those conditions because you are more comfortable.
Having hot flashes
My 2003 Yamaha YZF600R occasionally has an overheating problem. Every once in a while, the needle on the temperature gauge will go up either all the way to the hot position or close to it and stay there for a very short period, maybe 10 seconds, then drop back down to normal. It only does this after the engine has been started for the first time in the morning; so far, it has never done it during a ride when the engine is started and stopped during the day. Is something clogging the cooling system or does the bike have some other problem?
Dave Shelton Sioux City, Iowa
In all probability, the thermostat in your Yamaha’s cooling system is sticking. I’ve witnessed this same symptom in several bikes and cars, and every time, the thermostat was the culprit.
Located between the water pump and radiator, the thermostat is a heat-activated valve that allows the engine to warm
up more quickly and maintain the desired operating temperature. The critical component of a thermostat is a small, sealed cylinder containing material that has a high rate of expansion. A short rod connects the cylinder to the actual valve, which is a flat disc with a coil spring pressing against it. When the engine is cold, the spring keeps the valve closed to prevent coolant from flowing into the radiator, thereby allowing the engine to heat up more quickly. As the coolant in the engine reaches the thermostat’s predetermined
opening temperature, the material in the cylinder gets hot enough to begin expanding and pushing the rod outward; at the same time, the heat causes the spring tension to relax. With the rod pushing and the spring exerting less closing resistance, the valve opens, allowing coolant to circulate normally. And if during normal running, the engine’s temperature begins to drop below the desired level, the process will reverse just enough to partially close the thermostat, restricting the flow of coolant until the temperature rises to the prescribed level once again.
Occasionally, the valve can be reluctant to open if the little rod sticks or the valve disc hangs up. Corrosion or contamination in the cooling system can accumulate on these parts and impair their movement, and sometimes they just stick on their own. But at some point, the temperature gets so high that the rising force of expansion in the cylinder, working against the ever-decreasing tension of the spring, snaps the valve open, at which point the cooling system functions normally again.
Thankfully, the remedy is simple: Replace the thermostat. They ’re cheap and relatively easy to install.
Gimme a break-in
Some months ago, your test of the Suzuki DR-Z400SM indicated that the bike arrived at your offices with less than lOO miles on the odometer. In fact, a photo of the odometer on the bike’s LCD display showed just 155.1 miles. From the text and data in that test (such as the 0-90 time), it is apparent that you exceeded the owner’s manual recommendation of “less than Vi throttle for the first 500 miles” and “less than 3/4 throttle up to 1000 miles.” Do you think such break-in recommendations are unnecessary, or is it just that long-term reliability is unimportant for your purposes, since you do not keep test bikes? Stephen Hammack
Stephenville, Texas
Excellent question, and I’m not so sure I have an equally rational answer. In a perfect world, we would follow the manufacturers ’ break-in recommendations to the letter in the hope of extracting the very best from each bike for the longest period. But the world isn’t even remotely perfect. More often than not, manufacturers provide us with test bikes that have accumulated far fewer break-in miles than they recommend in their own manuals. On occasion, we’ve even received test bikes that have single-digit odometer readings! That’s the exception rather than the rule, but it’s nonetheless commonplace for test units to arrive here with fewer than 100 miles showing. When we get a bike with exceptionally low mileage, we try to ride it conservatively atfirst and avoid taking it to the dragstrip or running it on the dyno, but rarely are we able to strictly adhere to its maker’s recommendations. You have greatly simplified what is a very complex and expensive process. Even if another country s emissions standards are identical to ours, the bike is not automatically approved here. It has to be both EPA and DOT certified for sale in the U.S., involving considerable cost and time; those agencies don’t workfor free, and neither do all the Honda employees who have to take part in the certification process. And if a model that already is homologated undergoes significant engine revisions, it has to be re-certified.
Recall Roster
NHTSA Recall No. 05V537000 Harley-Davidson Dyna Glide-all models Model year: 2006 Number of units involved: 10.498 Problem: On certain motorcycles, the sixspeed transmission may go into a false neutral position, even though the neutral indicator light is illuminated. As a result, the transmission could drop into gear, creating the risk of a crash and subsequent injuries. Remedy: H-D dealers will replace the shifter drum, detent arm and neutral switch with newly designed components. Owners who do not receive this free remedy should contact Harley-Davidson at 414/343-4056.
Fortunately, this hasn’t proven problematic, largely because modern engine design and manufacturing, along with cutting-edge metallurgy and sophisticated oil technology, have removed most concerns about breakin. In a new engine, the components that interact directly need far less time to get to know one another; right off the assembly line, they fit together more accurately than in decades past, are made of materials that are more compatible and ride on films of oil that are more impenetrable.
This does not mean that the manufacturers ’ break-in recommendations should be ignored. It’s in an owner’s best interest to follow the guidelines as closely as possible to protect what usually is a significant investment. Chances are slim that a rapid, early break-in will result in diminished engine performance or a shortened service life; the question a new-bike owner must ask is, do I want to take that chance? If it were my bike, I’d do it by the book.
Oh, and by the way: We do keep some test bikes, including the DR-Z400SM mentioned in your letter. We’ve added it to our long-term fleet and will rack up 10,000 miles before returning it to Suzuki. And as coincidence would have it, the initial Long-Term update on the SM can be found elsewhere in this very issue.
The import importance
I’ve always used Cycle World as an authority to quote when the topic was motorcycles, so I figured you would be the people to ask. Aren’t the European emissions standards more stringent than ours? If so, why is it so difficult to get European models into the U.S.? I would really like to get a Honda Deauville, but the EPA basically says not without passing all the emissions tests. Another related question: Since you communicate with the higher-ups in the Honda organization, you might ask them about instigating a system wherein people in the U.S. could order certain low-volume models (like Yamaha does with its FJR1300). That way, we could get some of the European models here-especially those that are already homologated, like the new Trans Alp. Worth a shot, don’t ya think? Barrie Foster Garland, Texas
What ’s more, a company can’t just bring a small number of a foreign-market model into the U.S. and leave it at that; it has to be accompanied by all kinds of support material and equipment. This includes owner’s manuals, parts manuals and shop manuals, all in English, all specific to the American model; a complete and sufficiently large stock of spare parts; training and technical documentation for its service department personnel and regional service reps; an adequate supply of special tools needed for repair and maintenance of that model; a minimal amount of promotional material, such as point-of-purchase brochures; and some form of advertising, however nominal, to let American enthusiasts know that the bike is available here.
That considerable expense has to be weighed against the potential revenue generated by the sale of a small number of units. Until a company believes the financial outcome will be written in black ink, it is not likely to import such models. Yamaha has successfully done this with the F JR1300, but that bike has far more sales potential here than either of the two you mentioned. □
Got a mechanical or technical problem with your beloved ride? Can’t seem to find workable solutions in your area? Or are you eager to learn about a certain aspect of motorcycle design and technology? Maybe we can help.
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