Kawasaki Z1000 “Flatliner” by JM Customs

Kawasaki KZ1000 Street Tracker

A Z1000 street tracker straight out of Scotland…

The Kawasaki Z1000 — aka the KZ1000 in the North American market — was a direct successor of the legendary Z1, the most powerful four-stroke motorcycle ever produced at the time of its introduction. The KZ1000J, introduced in 1981, was a return to Z1 form, with an air-cooled 998cc motor that offered 98 horsepower, resulting in a quarter-mile time of 11.6 seconds at 130 mph. Z1 freaks could come home again.

Kawasaki KZ1000 Street Tracker

Enter James Moir and Chris Burnett of Scotland’s JM Customs, who are living the dream, building an assortment of custom bikes. No matter the genre of bike, from cafe racer to chopper, they have one goal in mind:

“Wicked machines that evoke the most maniacal of grins on our clients’ faces.”

This 1981 Kawasaki Z1000 was built for a local tattoo artist and friend, who gave them free rein as far as the design and budget. The result is this aggressive liter-size street tracker dubbed “Flat Liner” — a play on “flat tracker” and the LED heartbeat lines in the side panels.

Below, we get the full story on this maniacal Z, along with some killer shots by Oliver Young!

Kawasaki Z1000J Street Tracker: Builder Interview

Kawasaki KZ1000 Street Tracker

Please tell us a bit about yourself, your history with motorcycles, and your workshop.

My name is James Moir, I am Owner/Founder of JM Customs. We are a small custom shop based in Perth, Scotland. We design and build all manners of Motorcycles from café racers to choppers. Having always had an affinity for design and fabrication, and a love for the freedom that motorcycling allows me. It was an easy decision to make, to pursue A career as a Bike Builder.

I had been working in the oil and gas industry as a technician for over a decade, and the mundane day to day was something that had to go!

As the saying goes “It’s not a job if you love doing it.” And so JM Customs began.

We are a two man team here at the shop. I take care of the design and fabrication, and Chris Burnett, my lead mechanic, makes sure that our motorcycles not only look good, but function as daily riders.

Chris is a motorcycle mechanic with over 14 years in the trade. He has an absolute wealth of knowledge in all things two wheels, and is the most positive guy to have working alongside me in the workshop.

We both approach each day with an unwavering amount of energy. We are quite simply living our dream being able to create wicked machines that evoke the most maniacal of grins on our clients’ faces.

We also have a fully equipped service & repair workshop in which we keep the local biking community on the road.

What’s the make, model, and year of the bike?

The bike in question is a 1981 Kawasaki Z1000 J

Why was this bike built?

This bike was commissioned by a good friend of ours, a local tattoo artist Gary Weidenhof. We had had several discussions about a Z project and how he had always wanted one.

What was the design concept and what influenced the build?

The brief was simple in our mate Gary’s terms. No budget. He didn’t want to see it until it was finished. And he wanted something that was completely different to the bikes he had previously seen. For us the concept of this bike was an aggressively styled Tracker, with industrial looking features. We also wanted to add a modern edge to the bike to breakaway from the norm of Zed customising.

Kawasaki KZ1000 Street Tracker

What custom work was done to the bike?

We utilised many parts from a donor ZXR750 for this project. We took the swing arm and rear wheel and grafted it into the Z1000 frame. Machining new swing arm bushings to be able to take the original pivot bolt and converting the mono shock swing arm to a twin shock to give the rear of the bike a broad stance. The rear shocks are YSS shocks.

Kawasaki KZ1000 Street Tracker

We also used the front wheel of the ZXR on this bike too, allowing us a twin disc upgrade of more modern brakes for more stopping power. The front forks are from a ZX9 as they are around the same size in length as the original forks, keeping the stance at the front high, and giving us the clearance needed for the headers.

Kawasaki KZ1000 Street Tracker

We used the ZXR750 yolks and machined an alloy collar to allow us to press the original Z1000 steering stem into them for a sweet conversion to USD forks. We wrapped the upper tubes of the forks in Carbon Fibre vinyl.

Kawasaki KZ1000 Street Tracker

We wanted to keep the key features of this bike such as the tank. But importantly the iconic tail piece from this era of Z1000. The original seat unit was badly damaged so we cut the tail piece off and crafted a fibre glass tracker seat unit. There is an LED tail/stoplight hidden behind a grill in the rear of the Seat Unit. We took the side panels, and cut out Heartbeat lines in them, and build LED light boxes inside each panel, controlled by a switch located on the sided of the bike. They give the appearance of a heartbeat upon the bike. We installed riser bars, a KOSO speedometer, and a modern headlight with an industrial-looking grill to add to the theme.

Kawasaki KZ1000 Street Tracker

We custom-fabricated the exhaust headers, and installed two short aftermarket cans (minus the baffles) ha ha.

The engine got a full rebuild, as it was in several pieces when it arrived. And we didn’t know a thing about it Chris tore it down and fully rebuilt it. But this time it was reassembled with an upgrade. A big bore kit. Chris opted for a 2mm oversized piston kit.

Kawasaki KZ1000 Street Tracker

We rebuilt the carbs and tuned them to run with the newly-built engine and custom exhaust system.

We painted the bike in flat grey, with gloss black side panels, frame and wheels. Wrapping the rims in Continental TKC80s to complete the extreme look.

Kawasaki KZ1000 Street Tracker

How would you classify this bike?

We would classify this bike as a Street Tracker. We liked the idea of a blown out flat tracker, and with the heart beats in the side. We called her “Flat Liner” instead. You see what we did there? Ha ha ha!

Kawasaki KZ1000 Street Tracker

Was there anything done during this build that you are particularly proud of?

With this build we are particularly proud of being able to create a unique Z1000J when there are so many modified versions of it out there , but most importantly utilizing the parts we had available to us and pushing our Built Not Bought ethos.

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One Comment

  1. Marco Senties

    I was a kid when road warrior come out when I saw Toe cutters bike,well til this day the KZ 1000 one of my favs…
    One awesome bike you got there.

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