That 4-cylinder Leader "Stretch" was the last gasp for Ariel. It was mentioned in the technical press just about the time I left N-V. It was a flat four, either 600 or 700 ccs, with dohc and shaft drive, usning a stretched Leader chassis. I understand there were two bikes made up waiting for the engines, but the fist bench runs of the engine showed that, instead of the expected 60 horsepower, it only put out around 22 hp.
The entire development budget remaining wasn't enough to re-design the engine and Ariel went out of business. Having had a Leader, I was skeptical that the bigger, heavier and supposedly more powerful machine would have been very dangerous if the cycle parts hadn't been beefed up. The 6" SLS front brake on the Leader was pathetic. I had two events where I thumped the back of a car in traffic because of it.
Other than its prodigious smoke generating capability and the crappy front brake, the Leader was quite a good bike. It could blow off the Sprites and Spitfires of the time, though TR4s and MGB's were more of a challenge.
Originally, the gas/oil ratio was defined as 16:1. The original owner of the one I had christened it as "Old Smokey". I contacted Ariel Customer Support to ask about using a lye (caustic soda to you Brits) to clear the oil build-up out of the exhaust system. I was worried that there may have been aluminum bits in there.
The reply was "No there are no aluminium bits in there, so a Lye solution would be fine. By the way, we have found, through endurasnce tests that the oil/petrol ratio can be reduced from 1:16 to 1:48 without detriment to the engine. By using Bardahl two-stroke lubricant, the ratio cvan be extended to 1:56". What a difference it made to the smoke.
Until we came to Seattle, I hadn't realised that Ole Bardahl was a Seattle legend, big into unlimited hydroplane racing and a multi-millionaire based on his prorietary lubricants.
