Because that is asking for the bearings to spin.

 

^^^are you serious.....is that really a serious answer. What theHELL does the crank have to do with the bearings spinning in a 2g besides that its in the location that bearing are worn.

 

i always thought it was the 7 bolt block that made them walk ? and i thought the 6 and 7 bolt cranks were the same other then being 6 and 7 bolt can one of you elaberate a little bit for me im kinda confused and a little worried cuz the shop that built my moter said that it would be fine and the only reason i did it is so i wouldnt have to buy anouther lightwaight flywheel cuz i already had a lightweight 7 bolt

 

Many different theories.... all a matter of opinion. Personally I would stay the f away from the 7 bolt crank. Especially one that has already been used.