Looking back: The 4.2-liter, 48-cylinder, world record-holding Kawasaki

Whitelock's eye-popping 48-cylinder "Tinker Toy" was built to put a full stop on an escalating arms race in the UK custom motorcycle scene – and it certainly did, becoming one of the world's most outrageous and iconic motorcycles in the process.

Whitelock has been a prominent name in the UK custom motorcycle scene since 1985. Simon Whitelock started with more straightforward builds back in the day, putting together two-stroke inline fours using engines and parts from different machines.

Before long, he moved on to more ambitious projects including some remarkable engines, such as a nine-cylinder "triple-triple" and an inline seven-cylinder. All were Kawasakis – and all were two-strokes.

There was a tendency in the local scene toward one-upmanship in terms of how many cylinders a builder could wedge into these machines, and at some point Whitelock decided to take the idea to its logical conclusion and end the arms race once and for all.

Thus came about the ludicrous, Guinness World Record-holding 48-cylinder Kawasaki two-stroke you’re looking at here.

Whitelock's Tinker Toy Kawa, named after a WWII B-17 Flying Fortress bomber, is assembled from six banks of eight cylinders each. The Kawasaki KH250 was selected as the donor bike for two main reasons: one, because it was super affordable, and two, because of how widely available it was.

Interestingly, the bike technically has 49 cylinders. Whitelock had to set up an additional 125cc cylinder to serve as a "donkey engine" in order to get this 48-cylinder behemoth started. The donkey engine is turned off when all the other cylinders are operating – similar to a starter motor.

Other than that, Tinker Toy runs a BMW K100 gearbox, an alternator that was taken from a car, and a unique engine block with modified fuel and ignition systems. Thanks to its profligate cylinders, it weighs over 1,300 lb (600 kg). To manage that heft, there's a Honda Goldwing front end and heavy-duty Hagon wheels with stainless steel spokes.

The exhaust is set up as a 24-into-1 on each side, and each of its six 8-cylinder banks has its own ignition and Mikuni carburetor. The actual gas tank, which is constructed from 150-mm (5.9-in) diameter stainless steel tubing, is situated between the middle and lower cylinder banks, while the "tank section" that you see on top is a stretched KH250 portion that acts as an enclosure for electrical and ignition components.

The project started in 1998 and wasn't finished until 2003 – and as is typical of many projects, some 80% of the work came in that final year, says Whitelock. The bike has an active permit in England and complies with all regulatory criteria.

Simon says the engine sounded just like a Rolls-Royce Merlin when it was first started. During the most recent attempt to start the machine, the engine "fired up" a bit but the bike didn’t quite catch. Since the starting motor worked without any issues, it seems that the jets of the Mikuni carburetors might be clogged. Fortunately, there are just six of these carburetors to deal with.

The bike was officially sold at the Bonhams Spring Stafford Sale in April of this year. Whitelock stated at the time of sale that he was prepared to assist the successful buyer in starting the machine.

Per Bonhams, £92,000 was the final selling price at the auction, including the buyer's premium. That's almost US$120,000, or roughly $2,500 for each bore – but a lot less than the "half a million pounds" Whitelock said it'd take to pry the bike from his hands when the above video was made in 2018.

"It's not made for speed," says Whitelock. "It's not really made for power. It was made to get in the Guinness Book of Records. It's got to be able to do about 120-130 mph (193-209 km/h)."

It's a remarkably tidy build for something so extreme, and while the riding position doesn't look like the most comfortable thing in the whole world, Whitelock has indeed ridden the Tinker Toy. It pre-dates Instagram by nearly a decade, but remains a staple "WTF" machine in motorcycle feeds to this day... And we can't see too many people coming for that Guinness World Record, either!

Source: Bonhams