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...

Rust bustin'

I started with the rear plates from the clutch basket. They appeared as bad as all the other plates.

 

The photo below shows the plates after about 10 seconds. the white in the water is the gas from the reaction, so the power supply was working really well.

After about an hour I removed the clutch washer (as rusty as the securing nut, and it was in really good condition). The black marks indicate where the red oxidisation was.

The rings took about as long and came out well too. there is little pitting so the damage is cosmetic. The rear drive plate is too badly damaged. I will have to examine to ensure it is the same dimensions as all the others - there are quite a few sets available on the net in great condition.

Rust removal set up

There's plenty of posts and information on electrolysis rust removal, so I'm just going to cover my set up briefly.

After using this for restoring old hand planes, I know that the smaller the bucket, the quicker the results.  The electrolyte is washing soda, using about half a cup to around 5 litres.

My positive anode is my old file, works perfectly here as it reaches the full depth of the bucket.  For the negative current, I bought single strand electric wire (90c/metre) and stripped the insulation as required.

Finally the power supply. Previously I have used a battery charger, with OK results. I am aiming for 12 volts and 4 amps. I found this transformer for under $30 at Jaycar Electronics. It is 240V AC to 12V DC @ 5 Amps - perfect. It is designed to supply 12V fridges, so should run for a while. I removed the plug end and fitted alligator clips.  Now to put it to work.

Clutch basket removal

After removing the clutch cover (6 blots and springs) I had to remove the basket. This wasn't too difficult - I used an oil filter wrench to hold it steady while I undid the nut.

After that I used a puller working against two of the clutch cover nuts hand tightened back on. Then it was time to inspect the damage. 

The back of the basket was pretty good; just a little rust on two of the springs and one of the rivets. I've got a plan to deal with that later.

The back of the inner basket looks worse, but most of the "rust" is grotty oil left over from the sump. There is some alloy corosion, but it is literally surface defects only. 

Flip it over and its another story.  Below is one of the clutch plates adn a drive plate. They are badly rusted and pitted. A new set of clutch plates is easy to get hold of but a little worried about the drive plates. These plates stack alternately in the basket.

The very rear of the clutch basket has one final drive plate with two spring/shims behind and these three plates are secured with a really fine wire in a tiny groove at the base of the castlations.

 

I am pretty confident about getting all the plates replaced, but these rear springs are a problem. Next step is rust removal...

Removed the barrels

I thought the saga of the front barrel was goignt o be a major headache. Fortunately, after another couple of days of penetrating oil I managed to get the piston to move slightly more than half an inch from the top of the cylinder. After that it moved quite easily until it got to the bottom inch.

I was already concerned about belting the top of the piston while the barrel was supported on timber (to protect the mating surfaces). After sleeping on it overnight, I though about one of those pilot type problem solving exercises. For those that remember Apollo13, Gene Krantz turns the problem on its head and asks what right? Well I then thought if the piston was at TDC, then hitting the barrel from underneath might be kinder. It worked well, in fact the barrel hardly needed much to move it and I could get away with hitting on the fin area.

So next move is stripping the engine accessories so I can split the crankcase and deal with the rusty guts!