Service

SERVICE

JOE MINTON

Unruly Savage

I have a small, but annoying, problem. I ride a 1986 Suzuki Savage 650 Thumper which I like very much except for the one bad habit it has. When I'm rolling down the street or highway and close the throttle, the engine invariably backfires a few times, sometimes through the carburetor, sometimes through the exhaust.

In residential areas or in traffic, these resounding pops and bangs can be embarrassing, especially since I'm 72 years old and should know better. Is there anything that can be done about this? I mean about the pops and bangs. not my age.

Kenneth R. Wildoner Kingman. Arizona

The usual cause of the popping and banging you describe is an overly lean mixture. It is normal for the fuel/air mixture to lean-out when you close the throttle. If the mixture is already vemy lean, as most street-legal motors are these dai's, there mnai' be some backfir ing. This seems to happen more fre quently with larger cylinders.

Some early8Os Japanese car buretors incorporated a special enric/zening circuit that would add fuel w/zeiz the t/zrotile was closed. The sole purpose of this circuit was to prevent the backfiring you refer to.

You can probah/r ga//i relief by removing i/ic p/zig oi'cr tile idle-mix lure SCrew and turn/Jig I/ic screw out a bit (one-ha/f to 0/ic turn should do ii,) 10 richen 1/ic idle mixture. You also miiar need to replace i/ic /(//c jet wit/i i/ic next-size-larger jet.

Cruiser parts

I have a problem concerning my particular classification of motor cycle, which happens to be a cruiser. I own a Honda Shadow 1100, and for some reason, there doesn't seem to be too many outlets or mail-order services for cruiser-type motor cycles. Is there such a place? I know there are plenty of Harley-Davidson parts outlets, but I can't locate a place that specializes in accessories for Japanese cruisers.

Larry Sitten Roseland, New Jersey

As far as we know here. i'our Honda dealer is the on/v supplier of acces soriesfori'our Shado~t'. Honda 1~ "Honda/inc" division can supply windshields, saddlebags and engine guards. Honda/inc may have sommie oilier items you camz use, depending on which year imiodel you own.

The basic reason for the lack of accessori' parts for most Japanese cruisers is sinip[[r 1/ia! ther change often enough to discourage afierniarket nianufacturersfroin producing an extensive line of acces sories. When this changes-and with bikes like Yamaha `s long-running Vi rago series, it already is-you can be sure 1/ia! you ii'ill be able to find plenty of accessories for your Japanese ciii ise,~

Isn't that Special?

I have a 198 1 Yamaha 1100 Special with a special-built flatbed sidecar so I can operate the rig from my wheelchair. I have a couple of questions regarding upgrades.

What are the advantages, if any, of a leading-link front fork? If advantageous, who should I contact for such a fork for my bike?

Do braided-steel brake/oil lines offer any particular advantage over stock lines? If so, are the improvements cost-effective?

Any help you can give on these questions will be appreciated. If any of your readers have similarly equipped bikes. I would be interested in hearing about their setups and experiences. Thanks in advance.

William J. Newman Abilene, Texas

The main advantage of leading link forks over telescopic forks, when used with sidecars, is that they supply a significant anti-dive effect under braking. Front-end dive, which is a normal consequence of braking with telescopic front forks, will cause a sidecar rig to steer. Because most leading-link forks have their brake torque arms attached to the leading link itself, they develop a powerful anti-dive effect under braking.

Another advantage of leading-link forks on sidecars is that, since most of them were designed for use with sidecars, they have a more favorable trail dimension. Sidecar rigs work best when the front-wheel trail is less than is normal for single-track use. The old BMW leading-link fork allowed one to move the link forward in its mount and thus reduce trail for use with sidecars.

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Your Yamaha has rather soft fork springs and probably dives pretty far when you apply your brakes. You can gain some measure of relieffrom this problem by replacing its fork springs with stiffer ones. Works Performance (8730 Shirley Avenue, Northridge, CA, 91324; 818(701-1010) sells a cleverly designed fork spring set for your bike that is adjustable for overall spring rate and will allow you to tune your front end for your particular needs.

Braided brake lines will definitely improve the feel of your Yamaha's brakes, particularly the front brake.

All motorcycles built in 1981 had rather soft brake hoses which expand under pressure and contribute to a mushy brake feel.

Yamahas made through the early Eighties had soft disc rotors. These rotors would normally gall and score. While they will continue to function satisfactorily in this condition, they also contribute to a mushy, imprecise brake feel. Spec II (125 W. Verdugo RcL, Burbank, CA 91502; 818/8425187) will drill your discs with a pattern that will prevent and, to some extent, reverse the galling effect.

Finally, install Ferodo (compound 2453) brake pads. If you do all these things, your 1100 Special's brakes will feel and work much better than they ever did when stock.

There is no real advantage to steel oil lines beyond their appearance.

Imperial wizardry

In your January Service section, P. Foster of Knoxville, Tennessee, was curious about the high miles-pergallon figures he had read in some old tests of British machines. I believe he failed to understand that the British Imperial gallon is five quarts. This makes the mpg figures higher than with American gallons of four quarts.

Jim Toler Chicago, Illinois

True, but only if Foster had been reading tests published in British magazines.