the engine - in all its glory

So after deliberating the splitting of the engine case, I finally took the plunge based on some expert advice from BrynO and went for it.  Surprisingly enough the splitting of the engine was a doddle, and my fear of springs and cogs pinging out all over the place was cut short by the fact that everything stayed in its place.

Once apart, I could see the inner workings of the engine and before simply pulling it all out, I studied it carefully and with the use of a video from Youtube (found here), I was able to quickly see that it was relatively simple.  So, carefully I began pulling the various shafts and gears out, laying them on the bench in their respective order to enable me to get to the parts that needed replacing – mainly the rear hub bearing, 2 crank bearings and respective oil seals.

For a week or so nothing has been done on the engine as I have been waiting for the new parts to arrive – which they did today!

Without hesitation I was back on the engine and started by removing the clutch using the designated tool which had just been delivered, this allowed me access extract the crank, and therefore the bearings.  During this time I have also replaced the clutch plates as the originals looked as if they had pretty much disappeared (40 years old – it didnt surprise me).

Pulling the crank was easy enough and it exposed the main crank bearings – WOW, im glad I did this – I couldnt actually move the bearings with my fingers as they had simply dried up and got so much crud in them that it took a large force for them to simply budge.  Taking a large wooden drift and a healthy sized hammer, I pushed those suckers straight out and cleaned up the hole which was left.  Taking a piece of advice from Ray at allstyle-scooters, I heated the surrounding engine case before hammering the bearing out as he said that it can sometime crack the cases, I wasnt willing to risk it – so did exactly that and out they popped (thanks for the advice ray).

With all of the old bearings now drifted out of the cases, I drifted the new ones back in.  It felt lovely to be able to turn the crank over by hand with such smooth motion – it was all looking good!

Re-assembly was going quickly now, and with the new clutch back on, new bearings and oil seals I was ready to unite the cases back to their former relationship, of course with new engine gaskets.  I was rattling through the rebuild at a good rate now, so decided I wouldnt stop there – I grabbed the piston (with new rings) and cylinder (now clean and bead blasted) and assembled them to the main body of the engine.

Next was the gear selector, this went on without a hitch, apart from figuring out that I had to extend the selector past its normal operating zone to be able to hook it onto the selector pin in the engine, once this was done, it was bolted up – another piece done.

The carb box and carb came next – 2 bolts and a couple of gaskets later, and it was sorted.

Iv’e now come to the part where the stator and ignition systems need to be refit, but before I do – I think I will order some new parts, to be sure of smooth starting, including a new condensor, points and possibly a new coil.  Although these parts dont look shot, its difficult to tell as they are sealed units – better to be safe than sorry.

On that note, I think I will end here, however I have decided to build (with the help from Jamie, my friend and expert metal worker) to build an engine test stand which will allow me to hopefully start and run the engine outside of the bike, this will hopefully allow me to test and diagnose any issues I have with the motor without it being bolted into the bike.