Bottom end inspection and rebuild

[Steewhoop]

Hey guys,

I was wondering if it is possible to take the bottom half off the motor case off without taking the whole top end apart. I have a few old cracks around the two angled bolts right in the middle of the case in between the two oil plugs that are leaking. I have spare parts to replace the case with and would also like to inspect the internals as the bike was layed down and now wont shift into neutral. Thanks

 

[scabber]

The casings are machined and stamped in pairs like the heads.

 

[Steewhoop]

Bummer... so I guess I will have to try and weld cast aluminum... fun times!

 

[TwoManyXS1Bs]

Where are the cracks?



Fyi, those middle case nuts are acorn and have copper washers to prevent oil leaks.

 

[Muckroot]

Fyi, those middle case nuts are acorn and have copper washers to prevent oil leaks.

Dumb question, can I use regular zinc plated grade 8 m8 x 1.25 nuts from a hardware store for the bottom? I'm not worried about leaks yet, I'm just concerned the nuts will strip at 14 ft-lbs because they have about half of the thread contact as the two long acorns that came with the engine. (It was a parts engine, so a bunch of stuff was missing, including 70% of the bottom case nuts.)

 

[TwoManyXS1Bs]

Dumb question, can I use regular zinc plated grade 8 m8 x 1.25 nuts from a hardware store for the bottom? I'm not worried about leaks yet, I'm just concerned the nuts will strip at 14 ft-lbs because they have about half of the thread contact as the two long acorns that came with the engine. (It was a parts engine, so a bunch of stuff was missing, including 70% of the bottom case nuts.)

Sure. That's the way the original XS1s were built.
Replace them with the longer domed nuts later when you can...

 

[Muckroot]

Sure. That's the way the original XS1s were built.

Thank you! Also, any thoughts on replacing some of the case bolts (the 14 ft lb buggers) after the case halves are torqued together? Obviously I'm going to be replacing the six "oil nuts" with proper domed versions to keep oil from leaking in the long term, but I'm also rebuilding the engine with a friend and really don't want to wait for the nice fancy bolts (the four actual bolts that connect the back of the case halves, around the starter) to show up from mikes, so for now I'm going to use OEM hardware for those four bolts.

Basically, if I remove some of the case bolts/nuts to swap them for different ones will it mess up the gasket effectiveness or warp the halves at all? what process should employ? Also, when I do the swap, I'll have all the bolts/nuts I plan on swapping at hand, so I can do them all in the same day.

 

[TwoManyXS1Bs]

Do your bolt swaps, one bolt at a time. Remove, replace, torque to spec, then move on to the next bolt. Do this only on a cold engine...

 

[Muckroot]

Do your bolt swaps, one bolt at a time.

I kind of figured this would be the way to go, but I wasn't sure if just loosening every case bolt then re-torqing would be the way to go. I'll start with the one at a time method, and if my legs start getting soggy 100 miles in I'll do it proper and pop the side covers and clutch and re-torque the lot. Thank's for the info!