Just bought a 525 sx 2004 model,got the bike at bargain price because of gearbox problems,the guy i bought it from tried to rebuild it himself,bike sounds fine until you put it in gear,1st gear the bike will drive but sounds a bit clunky, 2nd &3rd are just clunky,4th is the same as 1st,the drive chain shaft seems to be a bit wobbly & if you turn it by hand it is clicky,any advice or help would be appreciated as i am going to try and rebuild the bike myself,4-strokes are new to me as was into 2-strokes which are qhite easy to work around,the engine is out of the bike as we speak,should i take this on myself or should i take the engine to a bike shop,what kind of money will i be looking at from a shop,cheers for any help advice,or comments,Dek.