Service

SERVICE

Honolulu lowboy

I own a 1983 Suzuki GS1100E. I’m thinking about buying a set of aftermarket wheels (wider, tubeless). What would be the effect of changing the front wheel from the stock 19-inch to a 17-or 18-inch rim?

C. Roper

Honolulu, Hawaii

In addition to 17-or 18-inch wheels being smaller in diameter than the Stockers, the modern tires that fit them have lower profiles than your Suzuki's original tall and narrow 19-incher. Consequently, such a swap would lower the front of your Suzuki quite a bit, reducing ground clearance. Incidentally, although the'83 GS1100 already has a 17-inch rear wheel, swapping it for a wider 17-incher— which requires an appropriate low-profile tire—would slightly lower the back of the bike, as well. This front-and-rear lowering could be a serious drawback, since'80-to-'83 Suzuki 1100s already suffer from marginal ground clearance during hard cornering. And we can only assume that improved cornering is one of the main reasons you want to upgrade your bike's wheels and tires.

In addition, changing wheel diameters can significantly alter steering behavior, not necessarily for the better. Installing a smaller front wheel quickens the steering by: a) tilting the chassis forward, which reduces the effective steering-head angle and front-wheel trail; b) placing the axle closer to the ground, which further shortens trail; and c) reducing the front wheel's gyroscopic stability by placing the greatest rotating mass (the tire tread and the outer rim of the wheel) closer to the axle.

We 've never made such a wheel swap; and the people we know who have done so also made numerous other expensive chassis modifications to compensate for the smaller wheels. We can 7 say, therefore, whether or not changing wheel sizes alone would be beneficial to you. But it sounds to us like you'd be creating more problems than you would solve.

Better-breathing Mini-ceptor

Last year, I bought a new 1988 Honda VTR250 Interceptor. I’m totally satisfied with it, but I would like to spruce it up with some sort of slip-on exhaust pipe. Unfortunately,

I have had no luck in finding anything that would fit my bike. Is there anything I can replace my stock pipe with that won’t completely empty my piggy bank?

Mark Berry

Altoona, Pennsylvania

Cobra Engineering (4760 E. Bryson St., Anaheim, CA 92807; 714! 7797798) has two slip-on silencers available for the VTR250. The cheapest is the Fl, a steel-bodied silencer with an aluminum outer shell, which sells for $70. The Fl-R is an all-aluminum version that retails for $129. Cobra makes no performance claims for these silencers, and instead say that their primary purpose is to give an exhaust system a racier appearance.

Whine connoisseur

My ’86 Honda VFR700F makes a loud whine upon deceleration. The noise seems to be coming from the engine cases. This happened after a hard launch away from a red light. My local dealer listened to the noise and doesn’t think it’s anything to worry about. The bike only has 1200 miles on it. Help!

Mike Ferrucci

Stony Point, New York

The VFR7001750 models do not have any chronic whining noises, so it's almost impossible to troubleshoot your problem accurately without more specific information—or the ability to hear the noise first-hand. But you might want to check for damage in the primary drive. The big primary gear on the back of the VFR 's clutch hub is actually two gears: one is the main primary driven gear, which is slightly narrower than the drive gear on the crankshaft; and the other is a narrower gear that sits alongside the main gear and is spring-loaded so that it always exerts pressure against the crankshaft gear. The purpose of this design is to effectively eliminate any freeplay in the primary drive for quieter running. If your hard launch somehow damaged this spring-loaded gear or its mechanism, gear whine could result.

Also check the mainshaft nut on the inner clutch hub for tightness. Your killer launch just might have loosened the nut, which could alter the mesh of the primary gears just enough to cause a whine.

The little FJ that couldn’t

I am very impressed with the current crop of Japanese 600s on the market. I own an ’85 Yamaha FJ600, and I am constantly reminded that it is an air-cooled, twovalve-per-cylinder machine. Would an air-intake kit and/or header application bring my bike up to (or closer to) today’s 600 sportbike standards? Or should I leave well enough alone and be satisfied with my quick, reliable motorcycle?

Scott Jacks

Lufkin, Texas

You could spend a lot of money on your FJ600 and never get it up to the standards set by today's super-sophisticated 600s. And even if you were somehow to succeed, you 'd have spent more money than the cost of a brandnew 600, and invariably end up with a less-reliable bike in the process. The FJ's engine performs quite well for what it is, but it was dated even when the bike first appeared on the market back in 1984; its basic design goes all the way back to a 400cc motor introduced in Japan in 1980. Then there's the FJ's chassis, which is, in many ways, even more outdated than the engine.

So, you inadvertently answered your own question in your letter: Leave well enough alone.