Yamaha XJ900 custom

Yamaha XJ900

Working in a small garage with a minimal collection of tools, Dimitar Kostadinov of Sofia, Bulgaria, produced this breath of fresh air. Based on a 1984 Yamaha XJ900, even Dimitar’s choice of machine defies convention.

Now 42, the builder says he’s been interested in motorcycles his whole life, but didn’t get his first bike, a Ducati S2R 800, until four years ago.

Yamaha XJ900
“I am in no way a professional builder, or even a mechanic,” Dimitar explains. “I’m actually a marketing consultant. But I have an electrical engineering degree and generally handle maintenance and repairs myself, so I am no stranger to having my hands in oil.”

He first noticed an XJ900 at a friend’s garage, and Dimitar instantly liked the rugged simplicity of the motorcycle. Details such as the air-cooled engine, shaft drive and no fuel pump made the Yamaha look, at least to Dimitar, like a bulletproof bike.

Yamaha XJ900
Dimitar found an XJ900 for sale and although the fairing and other body parts were cracked, the basic bones were in fine fettle. Exactly one year ago he tackled his winter project. “I had a few rules,” Dimitar says. “I wanted a rideable bike, not an exhibition piece. I wanted something street legal that I would be able to ride around the city. I also wanted to keep it close to the original chassis and components, as I didn’t want to invest too much in expensive aftermarket parts. Basically, a ‘budget’ DIY project.”

Yamaha XJ900
After the motorcycle came apart Dimitar shortened the rear subframe, fitted a homemade seat with a fibreglass pan, and produced a battery tray. The brakes, forks and wheels (with matching-size Metzeler Marathon tires) were rebuilt with new bearings and seals, and the engine was given a clean bill of health. Even the valve clearances were within spec, and the mill was simply scrubbed clean and given an oil and filter change.

Although it’s not impossible to fit pod filters to the four CV carburetors, Dimitar’s research suggested it might be difficult to get the jetting just right. So instead, he modified the stock air box with tubes connected to pods. The exhaust is stock, and he’s pleased with how the engine performs.

Yamaha XJ900
That interesting fuel tank was robbed from a 1970s Czechoslovakian CEZET 350. It needed significant reworking to fit the much wider frame, and Dimitar added a new petcock and external balancing line. The CZ also yielded its headlight and front fender, which was widened to become the Yamaha’s rear fender.

Instruments were extracted from the original XJ900 panel, and individual base pods produced from metal cups. The tops were turned from aluminum blocks, and various indicator lights replaced with LEDs. Original controls with new levers grace the Tomaselli handlebar.

Yamaha XJ900
Dimitar has enjoyed the last four months riding his café-inspired XJ900 in the city and on short day trips. He says, “I am toying with the idea of starting another build, but there’s just no space for a third bike in the garage.”