Yamaha Ybr 125

Hi, I'm new to this and don't know much about it. If anyone could help me, I'm having problems with my Yamaha YBR 125. It seems to be a problem with the fuel level sender or alternator, I'm not sure. Ever since I bought it, I've had starting problems. It went from bad to worse, and it seemed to improve after changing the battery, but this past weekend I hosed it down... and since then it hasn't started. It starts, but when I try to accelerate, it's like it's flooding and stalls. I put the fuel level sender back in, it sounds strange, and the revs don't climb like they used to. I don't know if I did something wrong when I washed it or if it's just the same old problem. If you could send me a manual or if anyone knows what I'm talking about, I'd really appreciate it, because I took it to a "Yamaha specialist" mechanic and he literally ripped me off. I still had the starting problem, which I suspected was the battery, and he did other stupid things, charged me 80 euros for nothing, and on top of that, it was leaking gas. Thanks in advance.