Crank inspection

 Looks bad? Like I mentioned previously, I am not down and out yet - I am happy that the bearing surfaces are going to be OK on either end of the crank, but if the rusty sludge has got into the conrod bearings then it could be a total loss.

Given that this part weighs a lot, I am not hopeful that ordering a replacement from overseas would be within the budget.

I also noticed this. A solid crack on the piston skirt. Doesn't look new, but it could have been from when I was trying to remove the engine accessories - I had locked the piston against the crank and might have damaged it. Hopefully that's the worst of it - I am expecting the barrel to need a rebore anyway s new pistons and rings are likely anyway.

And as luck would have it the bearing surfaces show wear but not damage! I will have to check the clearances but will do that after de-rusting.

Remove the crankshaft

 The plan involved using the tapped holes either side of the crankshaft. I had some 100mm long bolts but found that applying the pressure required was just bending the bolts inwards.

So I swapped them out for the shortest I could find with large washers captured by nuts. This worked fine with no heat applied.

 The remaining crank case half leaves the crank and transmission bearings and the middle gear assembly. Normally I would not be tempted to remove this, besides the fact that it requires special tooling, however, there are bearings in there that have been supplied by the same sump oil so I am expecting that they all need replacing.

Removing the transmission

Before I push the crankshaft out, I am going to remove all the transmission shaft/gear assemblies - most of them are just sitting in the left case half, and I don't want to try and piece them together if they fall out!

The two main shafts and the shift forks just lift out pretty easily The manual gives you the sequence and most of the parts (such as the forks) are labelled already. 

Removing the gears from the shaft is easy - just got to get the circlip off and they slide off. Worth noting here the gear selector drum is also pretty rusted. As it was the easiest to disassemble it went straight for de-rusting. A great example of how effective this process can be.

One of the things to be aware of is when the item is removed is to give is a really good wash in fresh water and apply some kind of protectant. I am using Lanotec - its a natural product that uses sheep lanolin in a spray can - smells like a shearers shed but works brilliantly.

Spiltting the case - Part 2

With all the bolts removed, I had to tempt the two halves apart. I was conscious that if I used a screwdriver between I would probably damage the mounting faces. So with my plastic mallet, I worked around the case and eventually saw a small gap.

After that, the cases split quite easily.

Well, I knew there was going to be a bit of a mess in here. First impressions were its not as bad as I thought. The transmission has some rust but not too much sludge through the gears, etc. The crank has a good covering, but nothing of note around mating surfaces so I think that will clean up well. The most rusty parts are the conrods, but more on that later.

In the following shots you can see  the amount of sludge in the sump. It has also made its way up higher in the engine, which is not surprising since I found some in the cam sprocket in the head.

There are a couple of o-rings here as well which will also need replacing.

 Next up is removing the crankshaft from the left case.

Splitting the case - Part 1

 Before I removed all the bolts, I had to remove some of the small parts that will easily get lost. The first one is the o rings. There's a mix of orange and black and all are in pretty good condition, except for one that looks like got squashed on installation. I will be replacing all of these.

Next is the locating dowel just above where the oil pump mounts. 

I needed to figure out a way of keeping track of the case bolts as I removed them. For all other parts, I made up a simple code which identifies which engine the part came from and either tag them or place in resealable plastic bags. This is working well so far, but won't work for all the engine bolts of differing sizes and lengths.  I figured a basic diagram was about the easiest way. This also helped me figure out the number sequence as the castings on the case vary.

Lastly, I found a couple of large metal fragments during disassembly. Being much larger than filings, I put them aside hoping to figure out where they came from and why. 

Looking at the engine case I found the spot (about 1 o'clock from the crankshaft below).  The parts form a king of catch all underneath the bottom cam chain drive. I think this part is there to stop the cam chain from falling all the way down into the case if it comes loose. I don't think there will be any problems if I leave it as is. I can't think of a way of repairing without it coming loose again.

Engine accessories continued

 Pulled the clutch in the same way as the stator. Found the rear has an additional drive system that is made up of a smaller cog that is driven from a spring connection - pretty clever but heaps of small parts to loose.

All the nuts, washers and cogs are plenty rusted and will all go through the electrolysis de-rusting process.

Finally, removed the oil pump, chain drive and supply line. The strainer was full of rusty oil and expect the same throughout the pipe and galleries.

Engine accessory removal

 I started to remove the accessories around the engine so I can split the case and start to deal with the insides. The easiest place to start is the gear selector assembly. It is only retained by a spring catch.

This is another part that has had a copped a belting at some time. As the photo shows, the keyed end is bent a fair bit. Fortunately I have a straight one on the spare engine, so I will leave this one until reassembly.

The next part to remove is the stator for the generator system. Should be simple however, because the barrels are already removed the stator just rotates the crank whenever torque is applied. I tried making my own strap type tool to hold the stator while i removed the retaining bolt. The nut is pretty rusted so that didn't come close to working. Then I noticed that there were a couple of tapped holes - awesome!

This elaborate arrangement of bolt, spanners and bench held it steady so I could belt the nut with a spanner. The next problem was removing from the end of the crankshaft. I tried the puller over a couple of days with a lot of penetrating oil. I ended up being concerned about damaging the stator (below). Sometimes it is better to stop and think through the problem.

So the solution was insert a couple of short bolts into the tapped holes with large washers on the end; use these for the puller to work on (meaning the puller would not damage the alloy outer rim) and then apply heat as evenly as I could. I heated the part for about 20 minutes ensuring there was a lot of tension on the pulley. I was about to quit when it suddenly released! Moving on...