Should have put this up a couple of weeks ago but better late than never.
My bike was leaking fuel from the LH carb, it was damp and a little wiffy (no puns) Well 2 strokes being what they are, like the wife not liking neglect, it bit me. Flooded out massively, almost had me walking home.
Anyway TDR's being what they are, (a big motor stuffed in a 125 frame) its a bit tight so off comes the offending carb. Open her up clean out the carb, nothing visible but there was dirt on the cloth i cleaned it with.
Whacks it all back together and........... nothing.
Std options first....
Change plugs, old ones were sparking but you never know.
Changed fuel, it had run on the stuff in it but....
Whipped the carbs out to drain them and check i'd put the LH one back together properly, finding the drain screw in the process that is blocked buy the other carb?
And..........STILL nothing.
Right, off come the exhausts and the carbs. Both pipes get the overnight with light caustic treatment. Carbs get the works, used an entire can of carb cleaning solvent and blagged my mates compressor to blow EVERYTHING out. Airways etc.
And.........STILL nothing.
Found the cause in the end, the cable outer for the LH carb had not seated properly meaning the carb was open around a quarter inch. As a result the choke won't work and even the good side will pull the easy way through the more open carb, weakening the mix further. Once it was seated properly it started next kick.
So to all those that post one liners saying they have checked everything, simple fact is you haven't. There will be something stopping the bike from running you just haven't found it. It may be something disasterous like a crank seal. But it is just as likely to be something tiny like mine. The cable outer was in the proper place but it needs to be pushed fully home so you feel a slight 'click' that was all i'd missed.
HTH
Enjoy