flapwick said:
But seriously now Mr. Wick. ;)
If you do decide to trade for the 426, there are a few things to keep in mind. Out of all of the modern thumpers of that time period, IMO the Yamahas were probably the best as far as longevity goes. The weak point, as others have pointed out, are the valves. On a used bike, you never really know how it has been treated. If you lose the head of one of your valves, you will most likely have to buy a new cylinder head, piston and cylinder. Or maybe worse. If the valves have a lot of time on them, one of them could be ready to fail.
If it were me buying the bike, I would ask the mechanics to remove the left side cover and expose the flywheel. The flywheel has magnets on it and any steel metal bits and pieces that may be breaking up inside the engine will stick to it and be easy to see. Have them pull the oil filter and cut it apart. Look for metal shavings.
If they don't want to charge too much for it, you could also have them remove the top engine cover and inspect the cams and cam journals. If the cams are discolored or scratched on the lobes or the journals are worn or damaged, you don't want it. Damaged journals mean you have to replace the whole head. A little money spent now to inspect the inside of the engine could save you tons of money later. If everything looks ok, have them check the valve clearance while they are in there. Just takes a few more minutes.
Smell the oil. Does it smell fresh or does it smell like a dinosaur crawled in there and died? If it's been taken care of, the oil will smell fresh and look clean. If the clutch has been mistreated you will also be able to smell burnt friction plates in the oil.
Check the sprockets and wheels. Are the sprockets worn? Are the wheels true and the spokes tight? little things like this will tell you if the bike has been maintained and how much time it has on it.
If you trade for the bike and like it enough to keep it, you may want to do a top end on it right away. Replace the piston, camchain and valves. Use Kibblewhite stainless steel valves as replacement valves and you will have a good solid top end that will last for a very long time.
Like Holeshot said, those bikes had a good power spread and still have good power even today. For your size, it will be a good fit for you. I really did have a WR400 and it was a great bike. Rode it and raced it for a couple of years and sold it to a good friend of mine. He sold it to a friend of his who is still riding it today.
Like everyone has pointed out, buying a used thumper is a crap shoot. Take the time and spend the money now to check it out properly. It could save you tons of money and frustration in the future.
Just my $ .02 now only worth $ .005 and falling fast.