The Big Blue Beast: Kawasaki Z900 Drag Bike

Photography: Luke Ray.

I’ve been dreaming about featuring a drag bike in Tank since we first started pulling the mag together. Even the most extreme custom build for the street can’t compare to the visual impact of a stretched drag bike, but finding one from the right era was the challenge.

While modern bikes converted for drag are impressive they don’t tend to have the same style as the retro racer I was chasing. Then through sheer coincidence and good timing local Victorian Ben James dropped me an email with a couple of shots of his Kawasaki Z900 Dragger and we locked in a shoot.

Our original plan of shooting the bike out on the dragstrip was proving difficult so we fell back on a location that Luke knew well. We had our hearts set on capturing a burnout on film but now that we weren’t going to be at a track we needed a safe location, away from the general public which we had in the industrial back lots of Coburg, Melbourne.

Ben’s Z900 was originally built in Perth, Western Australia in the eighties by drag racing legend Ray Easson. Towards the end of that decade the Z was relocated to Darwin by Scott White a Pro Stock racer who ran it up until the early nineties, taking out a first place in the 1991 National pro stock drags. In the mid nineties Andrew ‘Froggy” Freeman relocated the bike to Victoria where he added a nitrous oxide kit and ran it in local events achieving eight-second runs on the quarter mile before stripping it down and storing it in his shed.

After a visit to the Lake Gairdner Speed Trials in 2005 Ben bought the bike from Froggy with the dream of modifying it into a salt lake racer. At the time all that was left of the Z was the frame, front and back wheels, swingarm, forks and some late model body work. Over the next 12 months he added the electrics back in and pieced together a new engine before heading back out to lake Gairdner. With handfuls of teething issue the Z made 135 mp/h (217 km/h) and it was back to the shed to undergo more development. By 2009 the engine had been upgraded to 1166cc and on its second Gardiner visit managed a top speed of 155 mp/h (249 km/h), an Australian land speed record that stood until earlier this year.

Next was to get the bike back out on the drag strip with the goal of achieving a nine-second pass in the ‘modified bike’ class. Ben hadn’t had any experience with drag racing before but thanks to his hard work on the engine, the Z clocked 9.88 seconds on its first run at Heathcote drag strip. That initial run made it pretty clear though that the bike needed drastic modifications. With the massive torque from the engine and the extra grip of the drag strip, Ben was finding it difficult to stay on the bike as it rocketed down the quarter mile.

Back in Ben’s shed again the Z was promptly stripped of its bodywork and foot controls. He purchased an original Z900 tank and side covers and had a ducktail rear end fabricated. “Then I decided while I was at it, bugger it that motors done, I’ll build a 1428cc engine!” Once the new motor was ready to go and the bike was looking much more like its original self (aside from the massive car tyre on the back!) Ben clocked a 9.3 second pass at 143 mp/h.

The original bike was a 1976 Kawasaki Z900 but only the front half of the frame remains. Up front is a set of Suzuki GSXR 400 forks holding an Akront rim with a small retrofit Kawasaki KLR 250 rear brake, “You don’t really need brakes on these things”. The rear end of the frame is a custom made half chassis with a box aluminium swing arm. The two piece rear wheel uses a massive Mickey Thompson slick car tyre (26x15x8) running 7.5 pounds of pressure and a GSX1100 rear disk brake.

The current engine, which will be retired in 2014, is a 1428cc brute. Built on a set of Kawasaki Z1000 cases the engine uses an MTC big block and Z1000J head, an MTC lock up clutch, 40mm Lektron carbs, an MSD ignition and an awesome satin black Vance & Hines 4-into-1 exhaust. Gears are shifted using a button on the drag bars that activates the air shifter without the use of the clutch lever and a two step rev limiter is used for open throttle launches. When Ben lines up on the strip the stage one rev limit of 7800 rpm allows him to sit with the throttle completely open then when the clutch is popped the second rev limit of 10,800 rpm kicks in.

There’s also plenty of custom fabrication work on the bike that Ben performed himself. His custom-made engine mounts and urethane bushes stiffen up the chassis and his offset sprocket setup aligns the front and rear sprockets around the huge rear tyre. Ben is currently competing in the national championships, touring around Australia and is positioned in 5th place. With a very real chance of taking home the championship. The goal now is for an 8.99 second run but to do that he’s going to need to complete his new high compression engine build.

When it came to the paint scheme Ben had a tough decision to make. Originally he was planning on giving the bike a stock Z900 paint job but that idea eventually lost out to Moriwaki. “Moriwaki was a Japanese tuning house like Yoshimura. In the early ‘70s Moriwaki produced race versions of the Z900, which competed at Daytona, the Le Mans 24 hour and all the Superbike races back in the ‘70s. Graham Crosby rode a Moriwaki “Monster” around the world and Wayne Gardiner got his big break riding one at Daytona”. Ben’s a big fan of the Moriwaki story so as a nod to their history the Z received the Moriwaki racing colours of blue complimented by a yellow stripe and plenty of classic Moriwaki decals.

After we finished shooting the Z it was time for Ben to fire it up in preparation for our burnout. I had positioned myself off to the rear of the Z to shoot some video and copped the full brunt of the start up. Once I’d recovered from the initial shock, which almost had me laying my own skid marks (toilet humour at it’s finest), I sat eagerly awaiting the rubber shredding. After a quick warm up and a splash of water under the rear end, Ben dropped the bike into 5th gear, clamped on the front brake, opened up the throttle and popped the clutch. The noise was deafening and even though the back managed to get loose the coarse finish of the street didn’t allow the wheel to spin for too long before it gripped and skidded the front wheel forward. Determined to put on a good show Ben rolled back for another try. Unfortunately the chunky asphalt still proved too grippy for the Mickey Thompson and the Z’s clutch gave way beneath all that torque. With a disappointed look on his face Ben gave us the bad news, but we had still managed to capture a few shots with the rear end smoking and some video footage to commemorate the event. “You’re always burning clutches in these things” he said with a grin and we called it a day.

This article first appeared in Tank Moto issue 02.