To Split, or Not To Split (was broken sump bolt)


Project collector
Top Contributor Supporter
Reaction score
Coldwater, Mississippi
Short of it is, I need to have a bolt extracted from my bottom case. The engine will be out before I go to bed tonight. I’m sure a machinist can deal with it like that.
I’m off this week. My vacation plans got canceled due to COVID-19. None of this was well thought out or planned.
My options:
Put the engine in the trunk and take it to the machinist. Fix bolt hole then put the engine back in the bike. (58k miles, 5th gear has a broken dog)
Split the case. I’ve had a replacement transmission on the shelf for 18 years. It seems a good idea to get that done now. Mr Stupid failed to remove the clutch and charging rotor. (I guess I can put the chain on easily enough and get them off now). What seals will I require? Partzilla the best option?
I bought a 1981 engine from Don Lawson in 2003. It turns over. Beyond that, I know nothing. Just go ahead and swap it. If it’s crap, I can ride XS Eleven to Arkansas rally.

This isn’t a good time for me to overhaul the entire engine. I have other priorities. I’ll be deep into my regular busy routine before any parts show up. So, it’s bottom case or nothing.
Maybe once you have the engine out and can get at it better, maybe you can get that broken part out yourself? I don't think the sump bolts bottom out in their holes so I'm thinking that broken portion should be pretty loose in there. I know there are many easy-out horror stories around but I think one would work fine in this case.
i'd use the left-handed drill bit in preparation for the easy out, and if the bit didn't spin it out itself, then I'd be wary of putting the easy out in...

also, be careful not to break the drill bit itself off in there from pushing too hard or having it bind somehow

if the machinist is reasonably close i'd take it to him unless the bolt practically falls out on its own :)
i've had the best luck with mike's seals. a lot of seals out there look like they oughta work but don't for some reason. the seals involved would be the crank, countershaft especially. if i didn't have seals, i wouldn't feel bad about trying to reuse the old ones. because -- they can all be replaced with the engine in the bike if they don't work. i'd put a good layer of your favorite -bond around the outside of the seals. if you have to replace them from outside one of those $5 eagle beak shaped pullers makes it quick and easy. pvc sink drain pipe makes a perfect drift for the crank seal
Do some price comparing. Last time I did, buying from Yamaha was cheaper .....

Will the engine come out with the starter in place?

Left hand drill bit failed. Also, I didn't get it straight enough, working under bike. EZ out got a little bite, but no joy. Piece of bolt sticking up. Punch and chisel no joy. I'll give it to a pro before I destroy the case.
i forgot about oem. i have mainly used mike's though. it's very easy to spend $50 at mike's on a one oz bag of very few parts... plus if a dealer orders the parts and you pick them up there, you don't pay shipping
Last edited:
Just mail me the motor, I can get that bolt out for you. :geek: :smoke: :laughing:
I'll vote for trying Don's motor if you can still kick it over. Lets you do the original at your leisure without rushing get it right maybe a bit of performance tweaking. Do a compression test before installing Don's?
^That's the best idea since or if there's nothing to indicate the new motor has some problem itself

regarding cheap _unbranded_ seals on ebay...ask me how i know all the seals can be replaced from the outside with the motor in the frame :)