So today, I split the cases
...and my thumb and finger :limp: (those crankcases are sharp!)
But to carry on where I left off (it seems ages ago)
Removing the exhaust: I actually didn't take many pictures of this. It went surprisingly well! All the bolts apart from two were removed without issue - the ones that caused problems were the rearmost hanger bolt and it's nut (with no access), and the bolt down by the rh footrest - this has a square captive nut, but it's locktited, and its cage is made out of chocolate. In the end, both of these were sawn off, to be replaced with nice SS bolts/nuts when rebuilding.
The get the exhaust off, I did have to bend/remove the bash plate rear mount, but after that, a few blows with a rubber mallet/boot had it free and off the bike!
Now, remove the airbox:
and the throttle bodies (and all the tubes/wires connected to the engine - follow the service manual here, or you'll miss something):
Another part of the process I didn't photograph :( Remove all the engine mounting bolts, and become perplexed as to why it hasn't fallen out onto your foot.
Then notice the two compression bolts. These have locknuts (same tool as the swingarm bolt locknut), and then you'll be presented with something smooth and round that you have to unscrew! These bolts do actually have 6 tiny flats on them, but I didn't have anything the right size to undo them. Solution: remove the LH engine hanger (again, this came off OK, no seized bolts!) and keep lifting/lowering the engine until it comes free of the rear compression bolt. This will be to be loosened for re-assembly. The complete engine weighs ~55kg... use a jack if you have one!
You now have a complete engine. Remove all the hoses etc from it, and you'll end up with this:
My PAIR valves has a slight carbon deposit... they will need replacing
Remove the head cover (from here, all the bolts are decent steel, and come out happily)
set the front piston to TDC (If you've already removed the generator cover like I had, you can still align the timing marks with a mark on the LH crankcase). Not essential, but makes removing the camshafts less 'springy'...
Remove the camchain guide. Then remove the camshaft journals. On removing the bolts, pressurised air/water came spraying out from under the bolts! Only tiny amounts, but it has been reported before. Weird.
Pull the camshafts
From here, it's all fairly obvious. Remove the heads:
Careful to grab the gaskets too!
and the cylinders! (both pistons are caked in carbon - I thought they'd be cleaner to be honest)
The pistons come off easily (apart from that the 'circlip' mentioned in the service manual isn't a normal circlip - more of a spring clip)
Then do it alllll again to the rear piston.
Crankshaft
Piston:
You now have this:
Continue following the service manual. Remove the oil pump (it looks like this:)
and remove all the gears you can. The next step is where I got stuck for several days - removing the generator rotor. Once the tool (essentially a M20x1.5 threaded bolt. There are two other places on the bike that use this thread - the output sprocket shaft, which you can't use until the cases are split; and the oil fill plug. Don't be a muppet like me and try the oil fill plug. It's plastic, and will be ruined...)
The difficulty is tightening the puller, while holding the crankshaft dead still, and with your third arm, holding the engine down. If you don't hold the crankshaft still, the camchain(s) can get caught up and do this:
(at least, that's how I assumed this happened)
That pocket should hold the cam chain tensioner. In this case I think I'm going to try JB weld, as a new crankcase pair (not available separately) is £1800.... I can get an engine for less than that!
The reason for trying to remove the generator rotor is to get to these two bolts:
but you don't actually have to remove the rotor to get to them. I removed the starter motor (2x 8mm bolts, plus a few blows from 'das mallet') and wiggled the starter idler gear and its shaft out.
servicable? or not even worth it?
Now you can get to (and remove) these bolts. Careful here - they're tight, and one they loosen, I caught my thumb and finger between my ratchet and the edge of the crankcase - it's really sharp, and cut quite deep.
You can then remove all the other bolts (highlighted by the service manual)
Now for the fun part. I was expecting this to be a really difficult bit, but it was actually easy. The Laser crankcase separating tool is worth every penny
Set up the separator like the image above, and slowly tighten the central bolt. You'll hear a clunk, and half the crankcase will have separated.
Now move the tool over to the clutch shaft and do the same (once the gasket between the crankcases is broken, the clutch shaft sticks in its bearing, so you will need to drive it all the way through with the crankcase separator)
Separated!!!!
Check the condition of the oil mesh:
It's worth giving the crankcases and all the bearings a good once over too.
Now. The gearbox.
Remove the shift forks and their shafts
And pull out the shift barrel (it's heavier than it looks)
Check out the bits I found in the bottom of the crankcase...
You can then tap out the sprocket shaft, and remove the gearbox from the engine (don't drop the washers)
Driving gear 4th:
Dissasembly is straight forward, though requires circlip pliers with small 'prongs'
These pictures are of the failed part:
I need to get some better photographs, but in the flesh you can see the normal dull grey failure surface, but also a shiny area surrounding a hard lump. It looks like this was a material defect. The other dog just has the dull grey surface, I imagine it got hit pretty hard! Amazingly, it looks like there's no other damage! I'll take another look tomorrow in better light (and concentration) but it should be a reasonably short body count
The only thing I'm now concerned about is the broken cam chain tensioner pocket. I don't think there's a huge amount of force on it, and JB weld should hold, but if it does fail it could be fairly catastrophic. I'm not sure if I broke it by getting the camchain caught up (I was careful, but...) or if it did get hit by a fragment of gearbox, but either way it needs fixing, rather than replacing. I'll phone around to see if there are any alu welders than can do it first.
