Okay so I found out that my motor knock was a spun rod bearing so here is the question. I rod and crank have a few scratches in them. Someone told me I could take real fine sand paper sand it out and put new bearings in is this correct?

 

If you're intent on reusing the crank, send it out to a machine shop. When you're talking metal to metal contact surfaces spinning at high RPM, you want as smooth of surface as possible, almost mirror which you won't get from sandpaper. Second, if you're only sanding on one side, you will make the crank out of round for that bearing, which is bad for a spinning part. Third, you'll most likely change the bearing clearance to out of tolerance as you remove metal to get rid of the scratch, making it so you'll need a different bearing size.

They should only need the crank and the rod to do this, and it will probably run you $100-200, maybe less if you know the shop. Since you've got the rods out, you may want to replace them. It's easy to grind a crankshaft, not so easy to do a rod, big end especially. If the rod isn't smoothe under the bearing, oil will get back in underneath the bearing and most likely you'll spin it again. Dezod has rod sets starting at $411, not sure what an OEM single rod would run you. I have an xB, and on those you need an extraction tool to get the wrist pin out, it's not a standard spring clip.

 

was ur motor knock like literally a knock? liek was it really loud and noticeable?

 

do not take sand paper to your crank, this is not a 350. take it to a shop and have them micro polish it.

 

dear god no sandpaper,it has to go to machine shop to be returned to claen surface.......it is cheap to do.......much cheaper than putting motor together twice.

 

Tear it apart, have the crank turned .010 and resize the rod that was spun.