Sunday, 21 September 2014

Engine rebuild part 1 (of many probably!)

So the engine is out and I've had the delivery of parts (including an extra delivery for the forgotten corks) so I took the engine to work and started stripping it down. I didn't get many pictures of the process but I basically started by taking off the most obvious bits first and kept going until I had nothing left to remove.  I did get stuck at a few points though. The first interesting thing I found was that I was correct to order a replacement kickstart spring as there wasn't one fitted at all! There were two main problem areas, first was the main drive sprocket on the crankshaft and second was the clutch carrier (not sure of the real name). The sprocket was done up really tight and I couldn't stop the crankshaft from rotating. After several failed attempts and a bit of head scratching I took it round to the local car garage and the nut was off in seconds using their air powered impact driver. The sprocket was on the further shaft in the pic below, the part with 6 stubs coming out of it is the clutch carrier and was the next problem I had to overcome.

The nut was nowhere near as tight and I could use a pry bar in the stubs to stop it rotating so that came off really quickly. Another trip round to the garage resulted in a suitable puller, but the first attempt failed when one of the bolts I used failed. A phone call to Villiers Services (who I had ordered the spares from) confirmed that it is on a taper and simply needs enough force (and maybe a bit of heat) to get it to come off. They described their set up and it sounded exactly like mine, only with decent bolts. The taper fit is apparently an interesting quirk of Villiers engines made under license, a Villiers made engine would have a splined fit and wouldn't need to be pulled off. Some better quality bolts were found, the puller borrowed again and I was ready to try again.


It's a little bit of a 'hammer to crack a nut' but it worked. It made an almighty bang when it did release (the other guys in the shop thought I'd shot myself and I thought I'd broken something) but I'm guessing it's not been off since the engine was built so it's not a big surprise it made some noise. I could then continue with the strip down and got the whole thing apart.


I then realised that the main bearings (particularly the chain side where there are two) are a little rough so I've ordered replacements as they are only about £4 each (I need 3). They're pretty sizeable beasts for such a small engine so it's a little bit odd they've gone but since they're so cheap I really don't mind replacing them.



 Whilst checking over the rest of the parts I had a closer look at the clutch adjuster which is renowned for being broken off by the kickstart. Mine was still intact so I decided to check it still turned so I'd be able to adjust the clutch. As soon as I tried the knob came off in my hand, on closer inspection the bolt had been cracked a long time and was only held together by about 10% of the material. This gives me a bit of a dilemma as I will need to be able to adjust the clutch but I can only find brand new (freshly chromed) adjusters which I'm not convinced will look right on the bike. The quality of the chrome doesn't look amazing (linky) but I still think it will look out of place. I could always rebuild it as it is so it will run for next Sunday and then address the adjuster at a later date. Either way I need to remove the broken stub which isn't going to be easy. If anyone has an opinion on the adjuster and how it will look, please comment. Actually, if you have anything to say about any aspect of the bike please let me know

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