Welcome to the club!
Yes, I own one CB1, and I think it's a funny bike. A little bullet around the town, sticks to the road if you get good tyres, brakes well and easy to handle (like a bicycle). I do like to ride it...
On the other hand, it's a "small" bike. I'm 1,83m tall, and for long rides I don't feel very comfy (my wife says I'm like a big frog riding a matchbox). The footpegs are high and under/behind your butt, while you are bending over the handle-bar, your weight on the wrists (the racing attitude!). I changed the handle-bar for a larger and higher one. It's better, but the footpegs... mmmmmmmh!
The power is in Hi-Rev. Very small torque in low range. It happened to me 2 or 3 times to stall at some cross-fires. But gently you can ride in the traffic around 4000/5000 rev... Easy to control.
Strong engine if well cared. Carburators and regulators a little temperamental. The carbs of the CB1 don't like to stay unemployed on a long term (1 or 2 months): starts become difficult or no start at all till the battery doesn't work. In the 90s Honda had problems with the engeering of the regulators on many models. Mine had blown the regulator before I bought it... And has been changed for a 150 CBR one if I remember well...
But more to enjoy than to complain, and nothing is perfect, hey!?
Finaly I do adore the design, the sound and the "on/off" style riding.
Good luck Hans and don't hesitate if you have more questions!
The CB1 came before the CB400. Main difference is that the cams were shaft driven, but the rest of the engine should be interchangeable with the CB400, of which there are many.
The question with cheap bikes is always: how much money would you have to invest to keep it running for the next couple of years? It could add up, then there's the down time for repairs, or maybe something blows up and you have to push the bike a few miles...
I recommend to get a decent CB400 with papers, spend around 80-100K and you'll get a somewhat reliable bike, a '95 or '96 model with a new paint job. Don't worry about the mileage, those engines last forever!
MY wife has a CB400SF in 100% condition. Yellow/Black paint job, chromed swing arm etc. But I know she wont sell it for less than 100k. Has book, tax, insurance Everything. Also a real eye turner.
I am speaking out of turn but she did mention before that since she never gets to ride it much any more I should sell it. I dont let her ride in Bangkok unless we are going outside of Bangkok on a run. Scared of her getting in an accident. Not because of her skills but because of the other drivers.
I will talk to her tonight and if she still says I can sell it I will post photos etc.
Currently have a mate who will ride it to Chiang Mai with us next month as she will be working and can't go now.
Yes, 50 KB that's around the price... Depends on condition, service and... the seller. Odometers, well, don't trust it so much...
Just listen to the engine (when hot, no kling-klong!) and check the smoke (no smoke of any color when hot engine!) and the leaks around. If you can, check the clutch (no slip) and the brakes: riding the bike gently (40/60 km/h) be light on the handle-bar and brake fermly front and rear brake. The bike must brake quick and straight without trembling (you feel this in your hands and "butt")... Then check chain and sprockets, and all the electic devices: must work!
True advice KZ, but I should say go up to 200/250 KB to be "quiet" with a "modern big bike"...
The CB1 production stopped in the year 1993, so these bikes are older than 15 years now. You can't find a CB1 quoting 100 KB or more... It would be a scam. The touch is betwenn, say, 40 KB and 80 KB for a "top-very-mint-amazing" one, not more.
The CB 400 came later. Good bike too, but the technology is not the same. Not same frame, not same engine and so on. Prices are usually up, depends of the year...
Here (spanish web site): www.cb1.cun.net
you can download for free the owner manual and the service manual.