I need to do the same with a new Ninja 500. Any suggestions or pointers? I'd bookmarked
this post for reference, but haven't done my homework with the service manual yet to see what I'm really in for. Are you shipping the core to Spears for the undercutting, or do you have someone who can do it locally?
I've done this on other bikes, just not this one. It'll be the same idea:
Engine out (means exhaust, cooling system, chain, all electrical connections, throttle bodies have to come out or be disconnected first - you might get away with disconnecting the throttle bodies and leaving them in the bike loose)
Remove side covers both sides and remove water pump and starting motor (easy)
I am not 100% sure on that bike, but you probably have to remove the flywheel and stator from the end of the crankshaft. On a Yamaha FZR400, this is a nasty son-of-a-,,,, of a job, because it will probably be next thing to seized onto the tapered end of the crankshaft. Don't lose the key.
Remove all bolts that go down from the top to hold the crankcases together
Flip it over, remove oil pan (easy)
Remove all bolts that go up from the bottom to hold the crankcases together
Lift the bottom case off the top of the engine. Cylinder head and pistons and cylinders etc can stay on. Shop manual says otherwise, but it's doable, just somewhat more fiddly getting things lined up when putting them back together because the shift forks will be hanging down loosely and need to be guided back into place.
Take note of the position and orientation of the shift forks (which will still be in the bottom case that you just removed) so that you can get them right when re-assembling.
It's a few hours of labour to get it apart.
Clean the engine as best you can while it is still in the bike. Then, after it's out of the bike, clean it again, now that you can get into little corners that are inaccessible with the bike together (block off intake and exhaust ports and crankcase vent opening to avoid getting anything in there that shouldn't be there). Clean, clean, clean. If there's no dirt on it, not only is it a whole lot more pleasant to work on, but it also means there's less risk of getting a piece of dirt into a place it shouldn't be, and not noticing.
Use ziploc bags and a magic marker to hold related groups of fasteners and small parts, to make it easier to identify what's what during re-assembly.
You will need information from the factory service manual concerning tightening torques and sequences.
Reassembly of crankcases requires using a sealant on all the mating surfaces that have oil on one side and outside world on the other side. Use a THIN bead, like 1mm diameter. More is NOT better. Put this bead towards the outside-world side of the connection, to encourage excess to squeeze outside rather than into the inside. Excess sealant is very very bad, and can clog oil passages.
For reassembly, the factory service manual will have you assembling the transmission and shift forks into the lower crankcase, which allows you to test operation before committing to closing the crankcases. If you've done this with the top end together and upside down on the bench, you will now have to figure out a way to put it together without having the transmission shafts fall out while doing so. It may be easier to do a test-fit as prescribed, to make sure you have the shift forks the correct way 'round, then transfer the transmission shafts to the upper case (upside down on the bench) and just guide the shift forks into the correct slots as you assemble it. Or you can tip the engine forward so that the crankcase split is sitting vertically, and put it together in that orientation.
