Service
SERVICE
Filter follies
Paul Dean
I do my own service work on my Honda and needed an oil-filter wrench to remove and install the bike’s spin-on oil filter. My Honda dealer told me that neither Honda nor any aftermarket supplier offers any type of tool to fit these filters. I asked the dealer how he got the filters off and was told, “The best way we can.” I thought this strange, because Honda has used these filters for quite a while. But all of the cap-type and band-type wrenches I had found at auto parts stores were either too big or wouldn’t fit properly on the end of my filter.
Recently, in the automotive section of my local Wal-Mart, I saw some 3/sinch-drive cap-style filter wrenches that I thought might fit my Honda; so, I took a spare filter to the store and, to my delight, found one that is a perfect match. It is made by the Rite-Fit Company, is called wrench-F, and costs just $4.50. If any of your other readers have run into this problem,
they should try to locate one of these automotive filter wrenches.
I wonder if my dealer just didn’t want me to do my own oil changes.
Rick Cucina Hempstead, Texas
It s more likely he simply is a poorly informed dealer. Honda indeed does make-and sell-wrenches to fit the two different sizes of spin-on oil filters used on its motorcycles. The part number for the wrench that fits > the large-body filter on older Hondas is 07912-6110001, with a Hondamatic Code of 1536606. For newer Hondas, which use a smaller filter, the part number is 07HAA-PJ70100, with a Hondamatic Code of 2584522. For those later models, Honda also offers an oil-filter “set” that includes both the smaller filter and its matching wrench. The set carries part number 15010-MWO-OOO and a Hondamatic Code of 4080842. After you get the set, you buy only the filters, either from a better Honda shop or from your usual dealer-after you have made him a bit wiser.
More teeth, less bite
I have a Kawasaki ZX-11C and have considered replacing the rear sprocket with one that has three more teeth. How would this change my performance in the quarter-mile? And how much will this increase the rpm?
Also, a friend of mine says the performance tests that Cycle World does are not always true. He believes that the Yamaha V-Max can outperform the ZX-11. How do you feel about his accusations? Charles W. Catron
Galax, Virginia
Your friend is free to believe whatever he wants. We, however; feel obliged to believe the facts. And in this case, the facts are that our computerized, third-wheel performance tests, which are extremely accurate, consistently demonstrate that in practically every aspect of engine performance, the V-Max is no match for the ZX-11.
In roll-on performance, the V-Max does outgun the Kawasaki; remember, though, that the Yamaha has considerably lower overall gearing than the ZX-11, which gives it a distinct advantage in top-gear roll-ons. But in quarter-mile elapsed times and terminal speeds, as well as in absolute top speeds, the ZX eats the V-Max alive.
As for the effect of three more teeth on the rear sprocket, I know of no one who has made that gearing change on a ZX-11, so / can only speculate. But I suspect that unless you also find a way (a wheelie bar, a longer swingarm, a lowered chassis or all of the above) to keep the bike from trying to loop over backward as you launch it off the line, quarter-mile performance will improve either just marginally or not at all.
Even a stock ZX-11 has the power to post lower quarter-mile ETs if it> could charge off the line more aggressively; but harder launches aren’t realistically possible without some of the aforementioned modifications. Lowering the gearing will make launches slightly more difficult, so any gains in acceleration could be offset by time lost getting off the line.
When you change gearing at the rear wheel, figuring the change in engine rpm or road speed is easy. This is because percentage-wise, the speed goes up or down exactly the same amount as the increase or decrease in rearsprocket teeth. If a bike has, say, a 45tooth rear sprocket and a 15-tooth countershaft sprocket, that yields a 3.0:1 final-drive ratio (45+15=3.0). When you add three teeth at the rear, you get a 3.2:1 ratio (48+15=3.2), which is a 6.7-percent increase (0.2+3.0=0.067) in final-drive ratio. You can arrive at the same number more easily, however, by simply figuring the percentage of change in teeth at the rear wheel. If you add three teeth at the rear by going from 45 to 48, you increase the number of teeth by 6.7percent (3+45=0.067).
Either way, the rpm at any given road speed in any gear will increase by 6. 7 percent as a result of this gearing change, and the road speed for any given rpm will decrease 6.7 percent. The speed that formerly required 5000 rpm, for example, will now have the engine revving at 5333 rpm. Similarly, the rpm that formerly propelled the bike at 60 mph will now move it 6.7 percent more slowly, which is just a fraction below 56 mph.
Gimme a brake
I have a 1987 GSX-R750 Suzuki that I’ve tricked-out with a VHR pipe, K&N filters, a Dynojet kit, a reworked shock, Michelin tires and a neat paint job. I’m happy with the bike except for the front brakes, which are still stock. I hate the mushy feel and all the play in the lever, but I’d rather not spend a fortune on an entirely new brake system. I know that these characteristics are typical of earlier GSX-R brakes, but are there ways to make them at least halfdecent? Dale Hoffman
Winter Park, Florida
Two reasonably inexpensive modifications can upgrade your GSX-R 's front brakes to a level that most riders would find quite acceptable. First, swap the stock brake lines for steel> braided replacements from the aftermarket. This will greatly reduce the brake’s mushy feel by eliminating the swelling that occurs in most stock lines when the lever is squeezed hard. Then replace the original master cylinder with one from a 1990 to 1993 GSX-R750. These units have a different piston diameter and leverage ratio that give a firmer feel at the lever while requiring less lever travel to activate the brakes.
Silent but deadly
In your long-term test report on the Suzuki GSX1100G (July, ’93), you said you had neglected to adjust the valve clearance, and that “Only now, at 11,000 miles, are the valves beginning to clatter slightly.”
It is my understanding that as mileage increases and valves wear, clearance between the valve stem and its actuator lessens, which tightens the valve clearance rather than loosens it. The peril, therefore, in neglecting valve adjustment is not that the action will become sloppy and noisy but that the valve will not fully seat and thus burn without ever making a sound. I would appreciate your clarification on this matter. William T. Martin
Miami, Florida
Actually, either a too-loose or a tootight condition can occur if recommended valve-adjustment intervals are ignored. In some instances, the continual impact of the valve head slamming closed against the valve seat will wear the contact surfaces of either the valve or the seat, or both. The wear usually isn’t great enough to impair the sealing properties of the valve; but it does cause the valve, when closed, to sit several thousandths of an inch higher in the head, thereby reducing or eliminating valve clearance. This is the condition you describe.
In other cases, wear of the valve head and valve seat is much less than the wear of the camshaft lobe and/or its mating follower. When this occurs, valve clearance increases, eventually creating the familiar clattering that indicates the need for adjustment.
Still, your observation is valid: Our long-term report inadvertently suggested that ignoring valve-adjustment intervals is all right so long as no audible clattering is detected. This was not our intention, and we apologize if the implication misled anyone. □
