When it comes to two stroke tuning there is only one name - Fast Bikes

tuning godStan StephensGet the tune wrongand you’ll find yoursmoker doing thisYou only getout what youput in...The RD500…“When the RD500 was launched in theUK it was on a stage with spotlights allover it. Anyway one of our lads climbedon the plinth and stuck one of our StanStephens stickers right under the V4logo. The bike was red and white and sowas our logo, it matched perfectly. Noone from Yamaha noticed and it stayedthere all show and even appeared in allthe Yamaha publicity photos in all themagazines. Fantastic…”I oweall mysuccessto theracers Isponsoredand It wasthroughthemwinningthat ourbusinesswas builtThe animal…“I’m working on a 611cc two stroke twinusing 350LC cases. A standard YPVS is a64mm bore with 54mm stroke, I’vetaken it to a 78mm bore with a 64mmstroke, I reckon it should be good for150bhp so I’m going to stick it in mysidecar. I could do it for a road bike if youwant, it would easily fit in a 350...”Two wheels good, three wheels better.Four strokes? Forget ’em• per cent of the bikes out there were tunedby us at the time. At the first we were the onlyones tuning but soon anyone with a filejumped on the bandwagon, but ours were thebest. We were never the cheapest, I actuallyused to make sure we were the mostexpensive, but we did all the development,others copied our work.”Imitation, they say, is the sincerest form offlattery and once you put your engine out onthe race scene it’s there for all to inspect.“I spent weeks testing two stroke motorson dynos before anyone else really thoughtabout doing it, getting everything spot on. I didtwo weeks solid once testing reed valves.Different thicknesses, tapers, using backingplates, you name it, but our bikes were quickand it got us the work.”This is Stan’s blank canvas;a motor out of the frameand ready to be tunedthe more hours you put intodevelopment, the more you learn ”As with anything there isn’t really anymagic to Stan’s tuning, it’s down todedication, hard work and a lot of practice,patience and experimentation. Trial and error,all driven by the fanatical need to win.How do you find out what the minimumsquish you can run on a head is? You keepskimming it until the piston starts to hit it.How do you find the optimum combustionpoint? You keep playing with the ignition untilthe detonation is perfect. The more hours youput into development, the more you learn.Stan’s team put countless hours in and madesure everyone knew that it was their bikesdoing the winning.“I always made sure our bikes looked good,in our red and white colours and with our logoon them,” remembers Stan. “I was looking atthe records a few weeks back, I’ve sponsoredover 160 different riders over the years,something I’m very proud of. I’m a racingenthusiast, I’ve always wanted to be a racer, ora race team manager or race mechanic.”Stan does give the impression of being afrustrated racer and at the track he treatedevery race his engines were in as a battle.The RG500“Again, up at the show Suzuki launchedthe RG500. One of our lads walked overand looked at the bike, asking all thesequestions in a loud voice ‘how many yougot coming in, when is the on sale date.’He had already sussed the bike, helooked inside the fairing and sureenough it had 398cc on the barrels, itwas the Japanese 400 version, Suzukihadn’t even made the 500 yet, theywere livid!”“Everything I’ve ever done I’ve done as awar. I don’t now, but in the 1970s and 80s Ihad tunnel vision. My big competition wasTerry Beckett, it was like North/South tribalwarfare. The paddock was unbelievable, therivalry between racers was so intense, but thefunny thing was me and Terry used to watchthe races together! But I always wanted to beathim. I treated tuning as racing. Watching myriders was just as exciting, I’d get indigestionfrom the adrenalin. But it was getting silly, therivalry between us was so strong that we werelosing money, blowing cash on engines just tobeat each other. Eventually we spoke andcame up with a pact, we said to each other‘let’s just stick to what we know and try andmake some money!’ The tuning I do now onLCs is exactly the same as in the 1980s, thedevelopment kind of stopped at the point.”But times change and although Stan isknown as a two stroke tuner his firm hasdabbled in four stroke tuning.“Two strokes were becoming less and lesspopular by the 1990s so I needed to develop areputation for four stroke tuning. I employedone of the best four stroke tuners around•92 august 2010 fast bikes mag.comfast bikes mag.com august 2010 93