Today I was able to continue building. I received the adaptor and sprockets. They all fit perfectly.

Also checked how the chain would fit. Could shorten it quite a bit.

Took a while to shorten it since I don't have the tools for this but I succeeded anyway.

Now it just needs some more tension but it was getting a bit late already so I'll do this tomorrow. Could be that I still have to take 1 link out, not really sure if I still had the bearing house in the front position. It has quite a bit of play right now. But from what I can tell the chain is sitting in a straight line, didn't even have to adjust the adaptor. It just sits all the way on the axle.

Good news after today! The motor is finally attached to the rear swingarm. The blocks were TIG welded onto it and it looks very nice. The welder also said that this weld would never crack. And even if it did, I could return to him and he'd repair it for free. So I think it's safe to say that it's definately sturdy enough. He did say though that the original welds on the rear swingarm weren't so great and those could crack some day, but well it's a Chinese quad bike so you never know what to expect.

Here are some pictures.

On the bottom the rear block was welded entirely as well, only the front block is welded about halfway since he couldn't reach it that well. But it's sturdy enough anyway. Don't really expect to ever get any problems with this.

I also attached the rear swingarm with motor back to the frame again. And then I came to the conclusion I was very lucky with the welding. Between the motor and suspension is only about 2 mm of space. Thought I'd have a lot more space there. But I'm in luck, it's just enough. And when the suspension compresses the space only gets bigger so no problems with that either. This way I only have more space to place the charger and the batteries so it's all good.

Now to wait for the adaptor and sprockets.

When I wanted to attach the rear swingarm to the frame again I suddenly saw some brake fluid on the floor. The hose between reservoir and brake pump was all wet. So I removed it to take a look. It's very small rubber en apparently not really resistant to dot 5.1 brake fluid. For now I replaced it with a fuel hose but I'll have to get something else for this.

Today I removed the paint of the rear swingarm on the spots where the blocks will be welded and the mount will be sitting. Did this with a steel brush drill bit, went pretty good.

Tomorrow hopefully a picture with the motor finally attached on there. I will probably also get the adaptor and sprockets this week.

Today I got the motor mount and the blocks back. The adaptor and sprockets aren't ready yet, will probably still take another week.

Everything fits well now and both of the blocks are now sloped which looks a lot nicer than such boring straight blocks.

Only a small problem because of the bad welding by the Chinese. On the rear there's quite some play between the blocks and the swingarm. On one block it's around 0,3mm and on the other 0,7-0,9mm. Wonder if this really matters to get it welded properly or if I'd have to add very small plates inbetween.

In any case I already contacted a welder nearby, going to wait and see what he says about it.

Very bad news today, there's a problem with the delivery of the batteries. Supplier in China was acting up and because of that there's a now a very long delay, the batteries will be shipped to the company I bought them from on monday. Then it'll take another 8 weeks before they actually arrive I think.
Also not really nice of the company I bought them from to not tell me anything at all about this 8 weeks ago. I could get my money back if I'd find the batteries somewhere else but they're the only official dealer in Europe. I could maybe get them from the US, but I'll have to check the price because I don't think it'll get any cheaper.
Here in the Netherlands is also a company selling them but I have to pay 500 euros more in total so I don't think I'll do that. Rather wait another 8 weeks. If it actually remains 8 weeks that is.

I also got the blocks for the motor mount back this week but one of the blocks doesn't fit very well and can't be welded like this. So this has to be modified again and will probably take another week.
I already removed the rear swing arm so the blocks can get welded on there soon. Didn't have to detach a lot so this went rather easily. I only came to the conclusion that the swing arm hasn't really been welded straight by the Chinese, because of this the motor mount won't sit perfectly flat on there. Will still have to get those blocks modified anyway so I'll have to see what can be done to even this out. Seems better to me if it's completely flat for welding, don't want any welding defects because of it. Space between the mount and the swing arm isn't really much though, maybe not even half a mm, but still.

The 2 bottom mounting holes aren't aligned well either of that one block on the right making it impossible to attach. No idea how this happened since I can clearly see the correct marks for these holes yet they were still drilled too high. To fix this either the 2 holes in the mount itself have to be made a bit larger or a new block has to be made.
Both of the blocks still have to be modified anyway, I asked for them to be sloped on the rear but now they just go straight. Doesn't really look so good.

But there is one good thing today. I received a sample piece of the material I want to use for the battery boxes, 3mm thick ABS plastic.

In any case it's very sturdy so I think 3mm will be enough. Just still want to see if it's easy to weld and try some other things. If all goes well I can order a few plates.