Quote Originally Posted by Powerabout View Post
the 2 stokes left the Gp bikes at the end of last year due to some lobbying by Honda

The 2-strokes actually left the top class of F-1 bikes several years ago (2002), and I would not doubt that Honda had something to do with it, but I think if you research it, cubic dollars had a lot to do with it, as it was costing the manufacturers that were left at the time, which were only a couple besides Honda, millions of dollars each year to compete with bikes that the technology to develop them had nothing to do anymore with what they were manufacturing for the worldwide motorcycle market due to emission requirements worldwide, i.e. 2-stoke versus 4-stoke.

They (sanctioning body/promoter of the series) made the decision to go to a 4-stroke engine, of 1000CC's at first, ran those for several years, then went down to 800CC's for a while, got those motors turning faster lap times than the 1000CC models with development, and now are going back to 1000CC limits as no manufacturer makes an 800CC engine for wide use on the road. It all comes back to being able to write of development costs for the road bikes and let the technology trickle down to them.

This brought Kawasaki, Suzuki, Ducati, and several others back to GP racing as the 2-strokes they were trying to compete with against others, were no longer competitive ( some never were, and some simply chose not to compete in the top class as they did not have product and the cost was prohibitive to develop it) against Honda and Yamaha with the two strokes they were building at the time as they had gone to 4-strokes on the road bikes, were not building 2-stokes anymore (at least in the large road bikes), and they were not willing to continue to spend the large amounts in development costs to compete when there was no payoff for the bikes they were making for sale to the public. I just saw a former GP rider who is now a promoter on a motorsports show last Sunday night talking about just the transmissions that are used at present in the GP bikes costing a MILLION DOLLARS per each.

I would not argue that Honda probably had some input into the formula, but the overiding reason for the demise of the two stoke was emissions and money being spent there was no longer any write off for or benefit in the development on the road bikes, as the road bikes had gone to 4 stokes for that reason (emissions). Plus of course that "Harley " sound versus the Japanese 2-stoke sound of "ring-a-ding-ding".

Would really be interesting to see just what could be done with a two stoke emissions/max power wise if carried to the state of the art as possible today with computerized fuel and spark delivery. It looks as though the outboard manufacturers have just stopped or cut way back on development of 2-stokes in todays economic situation, by going the path of least resistance of 4-stokes, with the exception of the Optimax from Mercury and the 2-stroke product from Bombardier. Even the small engine folks such as the manufacturers of lawn and garden, ATV, Jet Ski and others have felt the heat and given in to the 4-stroke trend. Of course they as mass market manufacturers also have BOD's to answer to and the profit motive to make, unlike the small specialized high performance builder such as GRM and VRP. That is unless the emissions police get really tough and don't want anybody to have any fun anymore.

I have changed the link shown previously in the earlier post referencing the NS500 to a better way to reverence the Honda GP bikes, both 2 and 4 stroke with more info.

ADD: My apologies to Tim Kurcz for hijacking his thread with the last few posts, but since I have always been interested in engine technology, especially two stoke type, when the "oval piston" comment was made I thought it would be interesting to some who may not have been familiar with the engine to give some reference to it.