Hi everyone. I thought id try getting some help here as all i seem to get on Facebook is the usual "it a shit Chinese bike" or "why not buy a better bike" comment.

I bought this bike effectively for £50 as i had an old mtb laying around and sold that for 200 which went towards the 250 for this! Lol. The guy claimed it was ready for mot which i knew wouldn't be the case as its £250 lol.

So the problem i have is, it runs and rides, gears change etc. But it runs lumpy, struggles to tick over and if i rev it the revs will randomly rise and stick and won't drop. I then have to hit the kill switch or it starts smoking. Could this just be the carb need balancing? I took the carb apart, cleaned it out and put it all bk together, new fuel also. The spark plug is very sooty too. I've played with the screw on the side for the air mix but can't seem to find the screw for the fuel. Any advice would be massively appreciated. Thanks.