Don Wales, nephew of legendary racer Sir Donald Campbell, unveiled the demon mower yesterday, ahead of a record attempt at Pendine Sands in Camarthenshire in February next year.
The current record stands at 80mph, set by Bob Cleveland of the US in 2006.
Wales already holds the world land speed record for a car driven by steam and is confident he can add to his record collection.
He said: "It is a really exciting project and I am delighted to be part of it. How often do you get to drive a lawnmower at more than 100mph?"
The high-spec machine includes parts from three different Countax mowers and has been carefully assembled at the company factory in Oxfordshire.
According to the Guinness World Records’ rules, it must still be able to cut grass after all the modifications.
The company were originally approached by the team’s project manager Stephen Vokins who is the driving force behind the Project Runningblade.
Vokins said: "This started out as a daft idea that everyone laughed at but nobody is laughing now. Be under no illusions — this is not a collection of blokes standing around in a shed wondering what to do until the pub opens. We have all sorts of experts on board: an aerodynamics expert, a fuel additives expert — all sorts."
Countax has been building the mower for the last eight months together with the project’s five technicians.
Other sponsors include Toyota, Honour motorsport, Beaulieu, Atol and Wessex Heart Beat.
The attempt will take place on 27-28 February.
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