The Black Vault

It took about three hours to change the chain from start to finish. At least an hour of that was fiddling with a bench vice and vice-grip pliers trying to get the pin through.

I used a piece of angle iron under the frame at the top of the shocks and raised that with two car jacks perched on a chair each side. I also tried to put a wedge under the front wheel but that was futile so I roped the front brake to the bar. Fortunately it didn't fall over... But I was worried about it.

... It was easy enough to split the chain because I had a tool to do it. But my chain-link tool is a tad on the small size and I couldn't get the pin into the slot with the pushing-screw IYSWIM.

And to make it more interesting I erroneously pushed the link clear through! (I didn't notice the pin becoming more difficult to push because the chain was new I suppose, and so I just screwed it right out).

I put the link in the vice with a link between so I could push the pin as far as the other side of the outside link, then used vice-grip pliers to pinch it closed once I got it on the bike, and my chain-link tool could manage the last 5 mm.

It sounds much nicer - like a hum. - But now I can hear the engine is a bit rattly. I wonder why? Maybe it's normal?

Next job ----------- The clutch.

I had the clutch in pieces of a similar 50 cc engine last night.

The clutch housing looks like a small straight-sided bowl. Inside there are three clutch plates. Two have fibre on only one side and one has it on both.

The only difficulty was me trying to get the clutch assembly off using a hammer and chisel. I don't have the correct four-pronged-tool for it. But I managed to get it off and fixing the gubbins doesn't look very difficult.

There were eight + screws on the exposed side of the housing. Four were there to keep a cover on the middle and were recessed. The other four were round-headed.

I could easily remove the recessed ones but the round-headed ones were obviously going to be rounded where the screwdriver fits in. I used vice-grips to start the screws turning. Would the correct tool for that be an impact-driver? I'm sure any screwdriver would have just rounded the insides. - But then I could have used a hammer on the end of the screwdriver and twist, but it was too late at night for that.

I am hoping the 50 cc engine's clutch is the same as the 90. We shall see.

The engine I used to test how to get the clutch off was seized. But that was only because it had been outside in the rain and the piston rings had rusted to the cylinder bore. And the coils had stuck to the flywheel.

so I filled the spark plug hole with CRC and used a rubber hammer and a chisel on the timing mark on the flywheel to nurse it around a stroke or two.

But the flywheel was pretty gritty so I decided to take it off to clear the bits out. Of course I don't have the correct tool, but I have got a pulley-puller, which after a bit of violence was fitted satisfactorily.

It didn't want to come off and it was four o'clock in the morning and I thought if it suddenly flew off as it was under a lot of tension it would be pretty noisy. So I was just about to slacken the puller and get some sleep when it decided to pop off and knock some tools off the bench and the flywheel itself ended in a stack of wood, which also fell over.

It's amazing what you can accomplish with violence and pig-ignorance, isn't it.

When you're removing the clutch assembly off of the unseized bike (the 90), you're going to have to use something to keep it from spinning. Honda makes a tool for this, but most people just jam something in the gears (a biggish coin usually works). You may also be able to keep it from spinning by simply putting the bike in gear ... but I'm not sure that will work with a semi-automatic type clutch like the 90 has.

I exchanged the old plates with ones from another engine.

The old plates obviously had heated and were worn.

I got it back the first time and I heard a noise when i was testing it on the centre stand - Then I realized I'd not tightened the four recessed screws on the centrifugal oil cleaner in the centre of the clutch assembly. (I had only put them in a turn or two by hand - intending to screw them down). I was doing the job in 15 minute spells as I had other work I had to do. perhaps I wasn't able to give the job the concentration it needed.

It shifted roughly but I couldn't adjust it of course until I'd fixed it.

* Of course you've got to get the muffler off , the kick start and the footrests to even have a chance of getting the engine cover off to get to the clutch.

So I put the bike on its side again, took it to bits again, found and tightened the screws and put it all back together again.

But this time the clutch was in the on position all the time and I couldn't adjust it.

In the end I wrecked the centre screw of the clutch adjustment trying to get it to turn. - It's jammed for some reason. - Ruining the screw was partly deliberate in the end. I had resigned myself to stripping it down again and I can use the adjusting screw and nut from another engine.

So for a third time I'm going to take the engine cover off and see what I've overlooked and hopefully it'll be a case of third time lucky.

One good thing to come from this is that I've got the time down a lot on doing this job, and I can do it faster the next (third time). It took all-in-all about 2 hours the first time. 30 minutes this last time and I'd say I could do it in a bit less when I wake up and try again.

Not a happy mael at the moment.

Happy this time.

What happened was that on the second attempt, the clutch-adjustment on the engine cover didn't slot into the middle of the clutch properly. It was damaged so I used another I had.

I'm a bit worried about the gasket after removing it three times. But pleased I've managed to get the job done.

I'll probably need to adjust it a few times until it's settled in. No problems.

I might reconsider leaving it in top all the time and actually use the gearbox. ... But then the clutch was dodgy from the start. Anyway - I now know they don't last forever, and the great thing is that I now know how to do the job.

Thanks.