Damaged Crankshaft

The biggest problem by far.  We have a main bearing failure on the crank.  And the crank is welded.

 And nicely welded too.  The factory only welded either side of the drive gear but this crank is welded all along.  And very beautifully too.  It's too bad as we will not be able to replace the single bad main bearing.

Damaged Engine Components

With all that shrapnel flying about inside the motor, there was bound to be some damage.  Here is some of it.  

Some of the small ends are scored and one is blacked with heat:

 This one is pretty black.

 Here are a couple of the pins:

 And the inside of the cases clearly shows where the clutch exploded and hit the inside.

Hitting the inside top of the cases and putting a dent in it which is visible from the outside.

 

 And taking a lump out of it too.

Engine Strip - Getting The Cases Apart

I had a couple of problems with the bolts on the cases.  One bolt which was recessed too much and didn't allow me to get a wrench on it squarely, got rounded off and kept slipping.  Until it was prized off with a six sided tight fitting long reach socket. I had been using a polygonal socket that had stripped the corners of the bolt rather than gripping the sides of the bolt, which is how the 6 sided wrench works.  You learn stuff every day. This bolt is right up against the side casing and requires a thin skinned socket.

 Not this fat thing that I was using.

 Which resulted in this nicely rounded off bolt head:

The other thing I did was to snap one of the bolts when I was using my new power impact driver.

Engine Strip - Preparation

 I've never done an engine strip before.  It always seemed to me to be a job that required a load of expensive tools and involved masses of complicated procedures.  I've always assumed that if I ever got one apart, I would never get it back together again.  Perhaps I am right.  In any case, it would not have been possible to ride this bike with this motor without doing this.  We have already taken out so much metal debris, it is likely that there are other damaged parts and more metal scooting about inside.  Let's see. Firstly, don't forget this little nut just under the sprocket.

Take out the top bolts first.

 

And this one that holds one of the cam tensioner running plates.

 You will need the pistons to be removed before the cases come apart - at least on cylinders 1 and 4.  Pistons look quite new.  Obviously the pistons and cylinder liners were replaced after the catastrophic clutch explosion.  Too bad all the other metal parts were left inside.

Next off was the clutch.
 
 Which, along with other parts in the engine, was retained by a nice APE nut.

And a very nasty stop washer and retainer.

And let's see if we can get the rotor off.  The nut came off really easily with my new power impact driver.

 Just as well I know someone with the right tools.

 But even that wouldn't get it off.

 So we left it on.