Graves Motor Sports Suzuki Gsx-R900
GRAVES MOTOR SPORTS SUZUKI GSX-R900
Sweet Sleeper
ONLY THE RED “GSX-R900” DECAL ON THE TAILSECTION gives it away. Other than that, you’d think the Graves Motor Sports Suzuki is a cleanly modified 750. Think again.
“We couldn’t make the 750 engine bigger reliably,” says GMS owner Chuck Graves, “and the 1100 engine just wouldn’t fit. But an RF900 engine fit the bill. It’s narrower and has a downdraft head; it made sense.”
This was far from a simple engine swap. With the help of GMS tuner and fabricator Michael Belcher, Graves began the tedious task of stuffing an RF900 engine someplace it didn’t want to go. The existing motor mounts had to be removed and rebuilt. Inside the frame, the cylinder head mounts were machined out, and corresponding lugs were then welded to the rear of the cylinder head.
The 900 engine didn’t remain stock for long. A custom carbon-fiber Air-Tech airbox now feeds pressurized air to a quartet of Sudco 39mm Keihin FCR carbs. Gun-drilled Yoshimura camshafts spin stock valves, and APE titanium valve-spring retainers fit into the GMS-ported cylinder head. JE flat-top pistons raise compression to 12.0:1, and stock connecting rods bolt to an APE lightened-and-balanced crankshaft to complete the bottom-end assembly. The end of the crank houses a Rohm Performance Machine adjustable ignition advancer.
A Suzuki factory-kit close-ratio transmission was slipped into the RF cases, and works in conjunction with a GMS “low effort” slipper clutch, which eliminates wheel chatter during high-rpm downshifting.
Belcher went to town on the chassis, fabricating aluminum fairing brackets, clip-ons, rearsets, even a thumbactuated rear brake. A Fox shock and Öhlins front end handle suspension duties, while first-rate AP Lockheed calipers and trick, Dunlop D207-shod Technomagnesio wheels help keep unsprung weight to a minimum. Wrapping the package is an Air-Tech fiberglass fuel tank and bodywork painted by Gerard Design.
Graves Motor Sports brought a strong runner complete with a speedo, turnsignals and stock mirrors. This isn’t a rocket with a flashlight taped on the front, it’s a complete package that can take you places most 750s will never see.
Jason Black
Graves Motor Sports, 7645 Dens more Ave., Van Nuys, CA 91406; 818/902-1942
