hi, i have a question, i am rebuilding my rm250 (1993) and i installed some new crank bearings and oil seals. when i went to put the crank cases back together i couldnt get them to go together. so i took it up to a motorcycle shop and they said i installed a crank bearings backwards..and they said i put on an oil seal thats to small.. the manuel dosent say that there is a right and wrong way to install one. and the oil seal...how can that be to small when i know that i ordered the right one. so can you install a main crank bearing backwards, and is the different oil seals for a 1993 rm250?? btw it was the gear shifter oil seal. their charging me $400 for this, and all they had to do was assemble the bottom end which means transmission crank and crankcases. i have talked to some other people about this and they say you cant put a main crank bearing on backwards, and one of them mentioned that sometimes mechanics can rip you off. is any of this stuff true??? thanks!!