Motorcycle Questions And Answers - MC Garage

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By Tim Carrithers, Photography by Courtesy Of Barnett

Q I am the owner of a 2003 Suzuki GSX-R1000. The "Smart Money" and "BB Gunn" stories in your December 2005 issue mentioned a fragile clutch on the '03 model. I have noticed my clutch being notchy. I tend to push my bike to its limits by riding frequently in the canyons and going to track days; I was wondering what your recommendations are regarding changing any part of the clutch. Should I change the clutch and clutch basket or the whole assembly? Can you tell me the benefits of changing one and/or both?
Tony Goodwin
Burbank, CA

Clutching Conundrum
We put your question to Pat Dunn, general manager of Barnett Performance Products since 1999 with 18 years' experience in the motorcycle business. He started road-racing sidecars in '73, winning three North American Sidecar Championships, and worked as crew chief for Barnett Racing's Chris Taylor from 1998 to 2001.

A "Clutch plates aren't rocket science, but people characteristically ignore all the parts around them. Hard downshifts at the track put severe backlash stress on the basket and the whole clutch. Those tabs around the outside of the fiber plates beat up the fingers of the clutch basket and cause a notchy feel. If there's any roughness where they work against the basket, smooth it out with a file-without creating too much extra tolerance there-or get a new basket.

"Check the bottom hub and the pressure plate for wear, too, because it's there. The first fiber plate you put into a clutch plate rides on aluminum, and the last fiber plate in the stack rides on aluminum. Everything else rides on steel. Some guys just check the plate stack and think everything is fine-they don't realize those aluminum parts are notorious for wearing down because of the aggressive fiber they work against. The surfaces might look nice and shiny, but let's say there's 10 MIL (.001-inch) worn off the bottom hub and 10 MIL off the pressure plate-they're 20 MIL out of tolerance.

"Taking that much off the stack-height-in addition to worn plates in between-knocks spring-pressure down to the point where it can't hold the stack together. You need to inspect everything once the clutch comes out. Get a factory service manual and read all the footnotes."

Baghdad Bag
I was looking around the PX here in Baghdad and ran across the best motorcycle travel bag yet: the Bugout Bag, manufactured by Bugout Gear (www.bugoutgear.com). It comes in black or ACU camo pattern. They have other models that would work great on trips, and all are reasonably priced. It has all the features a military serviceman or woman needs, which just happens to coincide with what a motorcyclist needs. It's rugged, water-resistant, easy to open and expandable, has cavernous capacity, multiple attachment points, removable shoulder strap, concealable backpack straps, side carrying handle, padded waist belt, padded back, internal frame, and it will fit in the overhead airline carry-on bins if you don't expand it to its maximum capacity.Because of the numerous mounting points, it would work as a huge tank bag or tail bag. It even has a handy location for a hydration system for those long rides, mountain hikes, Baghdad street patrols or whatever. The manufacturer wants $90, but it can be found for much less.
Raoul Rodriguez
SFC, US Army
Baghdad, Iraq

Screwed
Gentlemen, on page 121 of your March 2007 issue, you complain about getting the Phillips screws out of the carburetor float bowl. You need to use the proper tool. Those-and a lot of other screws on Japanese cars, motorcycles and other products for the last 20 or so years-are Japanese Phillips, specifically Japanese industrial standard JIS 4633B-3/1991 and DIN/ISO standard 5260. Note the dot in one corner of the cross formed by the slots on the screw head indicating it is ISO/DIN. The Japanese-style Phillips screwdrivers are available from Ames Supply Company (www.amessupply.com) and Katun (www.katun.com).

I'm surprised more people aren't aware of the fact that there are two different specs for Phillips-head tools. Using the normal American/European #1 or #2 Phillips screwdriver in a screw head with the dot on it will most likely strip the head on the first try with very little effort.

Cleve Thompson
Via e-mail

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