Replacing left case - Full Rebuild

[XSWestgate]

Hi All, i've got a motor that leaks/burns oil because it's been sitting for so long it needs at LEAST a top end rebuild (assumed valve seal and head gasket leaks, probably more). On top of that, the case has been cracked from a thrown chain (PO's fault, I swear) it's beed patched and doesn't leak much so it's not critical. However, if i'm going to be tearing into the motor, I should probably replace the case but wanted to get feedback on; first, will that work to swap out the case (I found a donor same year/model) and, second, how far do I have to tear it down to do that? Any magic tricks to make it easy?

Aside: at this point i'm reconsidering keeping this bike. if I sell/part out now, I could recoup most of my costs. If i move forward, my concern is I won't be able to recoup these costs. how much can a rebuild like this cost just for the seals and tools required?

Thanks for all your input.

 

[5twins]

You're looking at a few hundred dollars for the topend rebuild, a couple hundred more if you need to bore it. For the engine cases, they are a matched pair so should be replaced as such. The bearing holes through the sides along the seam are line bored with the 2 matching halves clamped together. Mix unmatched halves together and those half bearing bores on each case may not match up.

 

[XSWestgate]

Thanks for the info, it seemed pretty accurate for cost. i've finished the rebuild by putting all the internals from my motor into the new bottom end I bought off of Ronnie_d on this site!