The 426 Tony had in the YSR had a stroker crank and a big bore kit. It was like a 453cc motor. It was, at one time, producing like 63 HP to the rear tire. The bike was seriously fun to ride, but it was not the fastest bike on the track at the time. It was at a disadvantage due to the extreme weight that had to be added to the bike to make the frame sturdy enough to hold the motor in place. It would have gotten smoked by a fair rider on a RS125.
I only know all this because I am the guy pictured in the black/orange/blue leathers riding it in the photos on the main page. Tony and a few other guys helped me construct a YZ250 two stroke powered YSR back in the day. it was much lighter than Tony's 426 and thusly got around the track a bit better.
Brian was not around back then, but I would probably say that we would have had our hands full trying to keep up with Brian and his son Kinser on their KX65s.
Those Frankenbikes were more trouble than they were worth to be quite honest. The last thing I would do is try to make another one and then try to go fast on it. All that fabricating is fine if you have a professional do all the work, but most of the time they end up being a maintainance nightmare. Shit vibrates off, mount bolts break, things just don't work like they were supposed to. Stick to something the factory made, then just make small improvements, that is my $.02. That is coming from a guy who spent lots of time welding parts back on and waiting in line at the local fastener store.
Paul G
