i'm trying to figure out what bike i should be looking for.. first and formost i want a reliable thumper, that acts like a thumper, and looks like a thumper.. i do not want to have a new top end ever seasons, i do not want to put all new valves in all the time, nor do i want to adjust my valves every 10 hours. I ride mostly trails, single tracks fairly aggresive, but do not spend much time on the track... some but very limited. i guess i've heard such great things about the yz motor that i'm interested. they sound like it will fit the bill, i don't want to adjust valves or topends like the crf's (although i am a honda guy... for now) and am not a fan of the weight to power ratio out of a drz or xr 400. so... i guess i'm looking at these two.. how reliable are they with good maintence, of course on average... How much faster is the 450 than the 426 will i notice it in the trail how do they compare overall... the weight isn't as much a factor due to trails i just want somthing fairly fast that won't run out of steam, or smile factor, that wont leave me stranded in the woods... also the 426 with a 5 speed vs 450 with 4 speed... how are they geared.. and how well do each work? thanks, i figured i'd post here due to the knowledge base.