Anthony Serpa loves his ZX-7Rs. Plural. Actually, he's only had one at a time because his first Ninja, a year-2000 model, was stolen from the side of the freeway with a flat tire after he was forced to leave it and get help. His insurance company paid it off, and those of us with a great deal more sense than Mr. Serpa would have opted for something a decade or so more current. Not our little Canadian friend. He turned the payoff into an ex-demo, '01 model. And, through the labyrinthine set of connections managed by all Canadians living abroad, Serpa hooked up with our own Geek from the Great White North to have his 5000-mile pride and joy become...ta da...the latest This Old Bike.
Factory Pro's drop-in jet kit includes new emulsion tubes, two sets of main jets (still staggered in size, as are the stockers) and shorter slide springs. We also reset the float heights to 15.5mm, as per Factory Pro's recommendations--like we can measure to half a millimeter!
It's a good subject bike, actually. The ZX-7R has seen a long and illustrious racing career, and as a result remains an emotional favorite of Kawasaki fans everywhere. So as we ease into the '04 model year-a year without the ZX-7R and other stalwart Kaws such as the ZR-7 and the ZX-9R-it seemed appropriate to take a whack at the Seven and see what could be done.
Never forget that this is an older design-even working on it is a real pain compared with "modern" Kawasakis, a clear indication that there is such a thing as evolution in design and manufacturing-and there's really only so much you can do. We spent most of the time working on three areas-reducing weight, increasing power and taming the suspension. Oh, and there were a few cosmetic improvements as well.
Let's start with the engine, then. Kawasaki's 748cc inline-four has been tweaked and modified by various race teams-and punched out to 800cc for AMA Superbike in '03-but has never really gotten much attention in the streetbike world. California bikes, in particular, seem to carburet poorly, so our first order of business was to install a Factory Pro jet kit (800/869-0497, www.factorypro.com ). We used the K51-0.5 "drop-in" kit ($129.95), which includes new emulsion tubes, slide springs and an assortment of main jets. (Stock is 170 outboard/180 inboard; we used 168 outboard/178 inboard.) Factory Pro also sent along a BMC oiled-gauze air filter ($74.95). Unfortunately, the company was out of stock on its ignition advancer for the ZX-7R as the project came together.
The good, the bad, the ugly. The doorstop-quality stock shock axed by this spiffy new Fox Twin Clicker (right). This model does not have adjustable ride height, so we made changes on the chassis end. Mounting the remote reservoir took some patience because the Targa undertail obscured the intended location behind the passenger footpeg bracket.
While mucking about around the airbox, some three pounds of emissions junk went into the hopper, including the California-spec charcoal canister, air-injection valve and carb float-vent apparatus. Factory Pro's Marc Salvisberg recommended removing this flotsam and simply routing the carburetor vent lines into the airbox through an elbow fitting, which we duly did. "This mod dates from the old Kinko's Kawasaki racing days. I still don't know for sure why that valve is in there, only that [the bike] works fine without it."
After installation, we tweaked the setup slightly, adding one Factory-supplied shim under each needle to help cure a midrange lean spot, and turning the pilot fuel screws out from the recommended two turns to three to fix an off-idle stumble.
On the downwind side of the engine went a D&D Performance (817/834-8961, www.danddexhaust.com) full exhaust system. This is the company's 4-into-2-into-1 configuration with a polished aluminum muffler (part number 802-22A, $585). We'll say this: You can't be an introvert with this pipe. On our normal noise test-6000 rpm without load, with the sound meter positioned 20 inches from the exhaust tip at a 45-degree angle-the D&D belted out 109 dBa of raucous, wailing, four-cylinder ...um...noise. Even young Serpa, whose automobiles all have rumpity pipes, thought it a tad loud. We also have a few issues with the fit of the pipe. On this ZX-7R, the flanges for the outboard cylinders did not line up perfectly with the exhaust ports because the collector pipe was too close to the frame crossover below and behind the engine. The pipe needs to twist upward at the rear but can't. The center pair fit fine, as did the Y-pipe after the collector pairs and the muffler. One installation note for you Ninja owners: You must install the head pipe for the outboard cylinders first because it's stacked on top of the inboard set below the engine; nowhere is this suggested in the instructions.