Service
SERVICE
Paul Dean
A Shadowy pursuit
I just bought a 1996 Honda Shadow ACE 1100 that already had Vance & Hines Straightshot pipes on it. The guy I bought it from gave me a jet kit that came with the pipes but told me that there was no need to rejet. I think he’s wrong. The bike seems to run a bit hot, which tells me it’s too lean. I’m not even sure if the jet kit he gave me is the right one. It’s made by Factory in San Rafael, California. Should I rejet? If so, should I buy another kit, or is this the correct one? I also plan on installing a K&N air filter. I have no idea if the bike is lacking in performance because I have nothing to compare it with. Mike McAdoo Springfield, Virginia
You supplied no part number for the jet kit, so I haven’t a clue if it is the correct one for your Shadow. Factory sells jetting kits for dozens of different makes and models, so simply providing me with the company’s name doesn’t help me identify your kit. What’s more, I have no personal experience with that particular exhaust system on an 1100 Shadow, so I can’t be certain whether or not your bike needs rejetting. I suspect that it does, since bolting a less restrictive exhaust onto a bike that already had lean, EPA-pleasing carburetion usually results in a need for more combustibles in the fuel mixture.
One way of evaluating the jetting is to “read” the sparkplugs. This is a process that involves riding the bike a short distance at certain steady, predetermined throttle settings and engine rpm, then removing the sparkplugs and examining the condition of their insulators. This can be a dangerous practice, however, if you aren’t extremely careful about how and where you do it. It also requires the expertise needed to determine the state of the carburetion by examining the deposits on the plugs ’ insulators. If you choose this means of jetting your Shadow, I suggest you have it done by a local tuner who has performed the procedure many times in the past.
A better method is to have the jetting evaluated on a dynamometer equipped with a “sniffer,” which is the popular name for an exhaust-gas analyzer. By measuring the content of the exhaust, a sniffer can determine the fuel-air ratio of the mixture being burned in the combustion chambers. More and more shops are buying this kind of equipment these days, and if there is one near you, I recommend you take your Shadow there to have it jetted. Not only is this method much safer than taking sparkplug readings, it also delivers more precise and quantifiable results.
Rules of engagement I have a 1999 Kawasaki ZX-9R that is having trouble with the transmission. When the bike is in third gear and I give it throttle, the transmission makes a loud rattling noise and the bike does not move. I checked the gears, the clutches, the shift drum and the shift fork but the bike is still making the same noise and still does not want to move in third gear. Any help you can offer will be greatly appreciated. boyz Posted on America Online
First of all, I think we have a terminology problem here. When you refer to “the gears,” I assume you mean the gears in the primary drive, not the gears in the transmission. And when you refer to “the shift fork,” I gather that you are talking about the shift pawl on the shifter shaft, not one of the three shifter forks inside the gearbox itself.
The reason I assume these things is that your ZX-9R either has a severely bent third-gear shift fork (which is inside the transmission) or all of the engagement dogs have been sheared off of third gear (also inside the transmission). Either way, had you taken the engine apart and inspected the transmission, you would have noticed such obvious and severe damage. In any event, your Kawasaki ’s engine will need to be removed from the chassis, the cases split and the damaged transmission components replaced. Unless you are a fairly competent mechanic, this is a job for a bike shop or someone who has experience in the repair of motorcycle gearboxes.
Non-stop Duck
I’ve owned a 1999 Ducati 996 since new (12 months) and have put 5000 miles on it. Two weeks ago, I got stuck in stop-and-go traffic while attempting to get onto the interstate. Once I got on the interstate, the first 10 minutes or so were spent cruising, with occasional braking. At one point, I felt that the bike wasn’t accelerating as quickly as it should, and when I tried to exit the interstate, pushing on the rear brake pedal did nothing at all. I pulled over and saw that the rear brake disc was covered with a molten mess and brake fluid was dripping out of the caliper. Please take my word that I did not ride the rear brake before this occurred. So, what could have caused this problem? David E. Hill Ocala, Florida
Clearly, the rear brake was dragging while you were riding on the freeway. So if, as you claim, your right foot was not slightly depressing the brake pedal, something else prevented the piston in the rear-brake master cylinder from returning to its fully retracted position after you took your foot off the pedal.
The implications of a brake pedal ’s inability to fully return are considerable. Brake fluid tends to get very hot, either as the result of normal braking or because of the friction caused by the brake pads constantly “kissing” the rotors as the bike is ridden, even when the brake is not being applied. When the fluid heats up, it expands, and its only escape route is through a tiny bleed hole between the master cylinder and the reservoir, just ahead of the piston. If the brake pedal does not fully retract, the mastercylinder piston blocks the bleed hole, preventing any fluid from flowing from the cylinder to the reservoir. Thus, the fluid will continue to expand until it starts applying the brake; that, in turn, causes more heat, which results in more expansion, which causes more braking, and so on. Ultimately, the fluid will expand to the point where it either locks the wheel or-as with your Ducati-blows out the seals.
You should examine the brake-pedals pivot for any dirt or mung that might be causing it to hang up, and check the linkage to ensure that the adjuster locknut hasn’t backed off and allowed the length of the adjuster rod to increase. But more than likely, this problem’s origins are in the master cylinder. On a 996 Ducati, the only return mechanism for the rear-brake pedal is a small coil spring inside the master cylinder, just ahead of the piston. If it loses much of its tension, it can’t push the pedal back to its fully returned position. And with the very small size of the Duck’s entire rear-brake system, it’s comparatively easy to heat up the brake fluid-and thus overheat and subsequently weaken the return spring-if your riding style involves fairly heavy use of the rear brake.
To replace the spring, you ’ll have to disassemble the master cylinder; and because the entire rear-brake system got dramatically overheated, you should rebuild the master cylinder and replace the fluid. Of course, you ’ll also have to rebuild the rear caliper and thoroughly clean the rotor.
Suzuki unplugged
I have a 1982 Suzuki 600 that sat for about a year and a half, and now it barely will run. It starts fairly easily with the choke, but it won’t run below 4000 rpm when the choke is on, and it won’t idle at all when the choke is off. Even when it’s running at 4000 rpm with the choke on, the rpm drops as soon as I try to give it any throttle. The bike will not start without the choke, and no matter how long I let it warm up, it won’t run without the choke, either. I ran some Gumout through the carburetors in the hope that it would clean them out, but it didn’t help. I would greatly appreciate any advice you could offer about this problem. BldllC Posted on America Online
As a result of the bike sitting unused for so long, the main jets and pilot jets in the float bowls have gotten clogged. When a motorcycle is allowed to sit for a long time without any stabilizing agent in its gasoline, the volatile components in the gas evaporate, leaving behind a thick residue that can completely plug the small orifices in the fuel jets. The only remedies are either to remove all the jets and soak them in a strong carburetor cleaner or simply replace them altogether.
The engine will run only on the choke because the cold-start enrichener system uses completely independent metering circuits that dump large amounts of fuel into the intake tract. The fuel orifices in those circuits are much less prone to clogging simply because they are so big.
No choke? No joke
I own a 1993 Suzuki Intruder 1400 (bought it new) that has racked up more than 30,000 miles. It’s a great bike, but I do have a problem with the choke (coldstart enrichment) knob. When I turn the knob clockwise to the On position, it backs off as soon as I let go of it. This means no choke is being applied unless I keep my hand on the knob. I have the OEM shop manual, but it is of no help in regard to this problem. So, how does one adjust the choke cable? Also, I would like to adjust the pilot screws on the carbs because the bike has run lean at idle since new. Ken Heiden Colonial Beach, Virginia
The source of this problem is not in the enrichener cable but rather in the knob assembly itself Behind the knob is a spool to which the cable attaches, and behind the spool is a friction-generating spring washer. Those three pieces attach, via a single bolt through the center, to a small housing that mounts to the bike’s frame, just below the left side of the gas tank. The enrichener mechanisms on both carbs are lightly spring-loaded to facilitate
their full closure when returned to the Off position; the purpose of the spring washer in the knob assembly is to provide just enough friction to keep the return springs from turning the knob.
Therein lies the problem: Apparently, the spring washer on your Intruder’s choke knob has gotten weak enough to lose most of its tension. This is permitting the force of the enrichener springs to spin the knob back to the Off position every time you turn it to On.
The obvious fix is to replace the spring washer; problem is, it’s available only as part of a complete choke-knob assembly. So, if you’re not willing to “spring” for the whole unit, your only other options are either to sniff around some of the local hardware stores for a similar spring washer, or to try shimming up the existing spring with a thin plain washer.
The pilot screws on your Intruder are located in a recessed opening just on the airbox side of the carburetors. The EPA doesn’t want riders fiddling with their bikes ’ idle-mixture adjustments, so the mixture screws are obstructed by a metal plug over each screw opening. You can easily pop those plugs off by starting a sheetmetal screw into them, then yanking
them from their openings like popping a cork out of a wine bottle. The screws adjust the amount of fuel that is sprayed into the venturi, so they must be turned counterclockwise to riehen the mixture, clockwise to lean it out.
The cell
I have a question about the electrics on my 1974 BMW R90/6. When I fully charge the bike’s battery and go for a ride of about 30 miles, then come back and put the battery on my Deltron Battery Tender, it takes about 8 hours for the Tender to indicate a full charge. My local motorcycle shop tells me that the BMW’s charging system is operating properly, and the bike’s idiot light and voltmeter do, as well. I also own a 2000 Honda CBR929RR, and this problem does not occur when I put its battery on the very same Battery Tender. Is it possible that BMW and Deltron have a different definition of a “fully charged” battery? Lee Scham Houston, Texas
Not at all. Instead, I believe your R90 s battery has at least one weak cell. If the idiot light never illuminates while you ’re riding, this indicates that the alternator is delivering sufficient amperage to charge the battery; and if the voltmeter reads 13.2 volts or higher while the bike is in use, this indicates that the battery is achieving its full charge. The question, however, is not whether the battery can accept a full charge but rather if it can keep a full charge. If it has one or more weak cells, it will begin losing some of its charge the instant the engine is shut off. Weak cells also prolong the amount of time required for a battery to reach a full charge, especially when using a Battery Tender, which only charges at a rate of just over 1 ampere. With weak cells, your battery isn’t long for this world anyway, so replace it now 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.
